The number one piece of advice I have to give is to realize that becoming a professional gambler is a suckers game. Keep reading though, I am going to give you gold.
The reasons I say it is a suckers game is.
1. The very few that actually make money "gambling" don't make money "gambling" they actually work a full-time committed job (with over-time) analyzing statistics (player tendencies, past performances, knowing facial twitches better than the CIA etc.) they have no downtown time. They have to spend every waking moment learning how to exploit something from every possible ange, competing against a multi-billion dollar industry and/or the millions of other players who are all trying to do the same thing they are trying to do. It is not easy money.
2. Even if you pour everything you have into learning that one game there is no guarantee that you will ever be a profitable gambler. Again you are competing against a multi-billion dollar industry/and or millions of other players. The vast majority of whom, develop a sad, addicted delusion that they are profitable, despite solid evidence otherwise. Being a profitable gambler is not really a job even, the truth is that nobody knows what is going to happen with the turn of a card. That means that you never truly know that you are making money. It is like trying to navigate a long, dark tunnel at night time with rocks in it without having so much as the luxury of tripping and falling a single time. The vast majority will fall flat on their face and humiliate themselves, a few will develop their senses to a whole other level where they can make it through the tunnel without tripping. But nobody knows when the tunnel ends. Ask any professional when they will make their next payday and they won't be able to answer you, they know there is an end to this tunnel, because they have been there, but they have no way of knowing when that tunnel actually ends because, just like everyone else, they are navigating through it blindly.
3. It doesn't actually make sense. Even if you are willing to put hundreds/thousands of hours just LEARNING the game with no guarantee of success and risking a possible addiction that drive to suicide. Why would you? There is only one sure thing in life and that is that if you work a job for an hourly wage, you will make an hourly wage. So why not just work on developing an actual skill that you are sure will make you money. Being a dealer. Dealers invest all the time it would take (if not less) than professional gamblers do in mastering their game. With more or less the same amount of money earning potential as a professional gambler. The majority of professional gamblers are making around minimum wage (for a number of reasons, but one being that they don't have the necessary funds to finance a fantasy salary on the high-stakes) and there are some dealers that can make in the hundreds of thousands being tipped by the whales (super elite gamblers) for providing them with a means of entertainment. Some people in the casino industry even have the luxury of being able to get an unlimited amount of money to play with for the sake of bringing in these super-rich players.
Now that we have established that being a professional gambler is a suckers game. Let me tell you a little bit about what it feels like to be that winning player at the casino every one looks up to with envy. The truth is that gambling is an illness. When you see those guys in holllywood turning $5 into $1,000 or more. The only thing they are doing differently than you is that they have learned how to get a better high than a total rookie his very first time. It is all a matter of minimizing risk as much as possible and planning to play for as long as possible within your means. They are no different than that heroin addict that learns that shooting into a certain vein or timing their exposure to it will produce more of a high than simply dosing it all at once into the same spot all the time. Their goal is not to make money but to simply maximize the high that they get from their money. I am hesitant to even write down strategy for doing this because I don't think that it is necessarily "healthy" to crave to maximize your high as much as you can (it will probably just cause you to degenerate into an awful stupor just like me and millions that have come before me). So I will give you a chance to be smart and stop reading right now if you aren't already a hopeless degenerate.
So you have $5 what are you going to do with it? You play that money with as little risk as possible (making bets on roulette, for example that have around a 50% chance of winning or higher) you build it up till you have around $20
Now you have $20 what do you do? I would use a system called Oscars Grind (reason being with a full bankroll the odds of losing all your money is 1:5,000) on a table game with less than a $5 minimum bet. You play this money out and front till you to $100 the secret to maximizing your money anything greater than $20 is to plan for the long-term. You need a strategy that is going to allow for you to lose as many bets in a row as possible while still being able to overcome this loss. The trick is to have it not matter what happens on the turn of a card, but rather what happens on as many turns as possible. You need to stop caring about winning that hand, let go and just let the math take care of itself. (Mathematically you still don't win, but if you consider the odds of winning over one hand vs. The odds of winning if you take into account 10 or 20 hands, you are more likely to win during that session taking into account the short-term law of averages). When you get to maybe $100 start upping your base bet. So the trick is one way or another, minimize your risk factor as much as possible.
That's all there is to it, (amazingly, this works on slots too about equally as well) when playing slots, use the Oscars Grind principle, starting with the minimum bet and work your way to the maximum bet. If you reach it go onto a higher slot machine and repeat. Typically there will be 3 or 4 slot machines you will try your luck on. (Something like a penny game) then the nickel game, then the quarter game, then the dollar game. By playing on different machines and trying to last as long on a machine you are effectively bringing the game into the longer run. I like to avoid slot machines that force you to play multi-line as they are more expensive meaning bigger bets and the wins are typically not enough to cover the size of the bet you made. Even if it doesn't really matter, I like thinking I have the control of being able to maximize any wins I get to overcome the losses getting there, which I find that using multi-lines cause you to reach the end of your betting range too quickly. Allowing for single lines allow you to place more bets which makes you think that you are able to control the outcome a bit more. (Although I think that slot machines are preset with he amounts they are willing to payout, if there has just been a massive win, or a few smaller wins. I have a gamblers suspision that the machine will need some time to restore the funds needed for its next payout I am not sure if this is true or not) playing on multiple machines will allow you to have the opportunity to get more "luck" as you have more opportunities to strike it lucky if you try to get lucky on just one machine (assuming that it needs time to restore) or a whole bunch. I know math and casino minds will jump all over this on me but think about it this way. If you have a potential payout of 95% over the lifetime of the slot machine. I assume that in some way that reflects what happens over a series of 50 spins. If that machine has just payed out 100% of the money that the last 50 spins have taken in. It stands to reason that it will need to readjust itself over the next 50 spins to get back to its 95% payout range, if you try out multiple slot machines, then maybe the next slot machine has payed out around 80% of the money that it has taken in. If this is the case then over those 50 spins on this next slot machine I assume it will adjust itself back to its 95% payout range. This might be a total delusion (probably is) but it seems to work for me, whether it be the different machine or just upping your bet in an Oscars grind type fashion.
Consider buying professional gamblers advice. A lot of them are total degenerates who just have a delusion of winning, but a few minority have it made. If so it stands to reason that if you buy their advice then you will get their results. The site I have found which is pretty good is oddsworthbetting.com
Learn a little bit about the strategies behind all these games that have been tried and true to produce better results (always bet on banker in baccarat, learn basic strategy in blackjack, take advantage of comps and go only when there is a great offer comp offer for the player, learn how to count cards it's not that difficult) just browse twoplustwo.com, or google strategies in your chosen game but use discretion (a lot of crap is sold for good money when it comes to this stuff) get a basic understanding of game theory and if the advice seems to make sense based on that, use it, if not disregard it.
There you have it. Have fun. Play safe. Remember it is just a game.