Questions: Flirting

Is it fine walking up to a girl on campus and getting straight to the point and ask, if they would like to have coffee or lunch sometime? Just curious, if girls like guys who get straight to the point. I’m a college student and I though I’d ask this question to get some opinions.

Hi! Just like that.
I've been thinking about it for a while now.
I want to kiss my crush on our next date.

But, I don't know if I should ask her or just "steal" it.
We've been pretty close to each others mouths a couple of times before,
and I don't want to get rejected if I "just go for it".

If the time was right, and we were that close again, should I give it a try? (Life is short)

Back in the day, sometimes I asked for it, others they just kissed me.
What do you do nowadays? Do you ask for it or "go with the flow"?
If so, what is the best way to ask for it? I want to read your lines, guys and girls! I need ideas.

Anyway, Thanks for your time and for reading!
Peace!

I turned 21 a few months back, she's 17F. I met her online in a game a few weeks back and we've been talking since. I really like her. Today I asked for her Snapchat. Not sure how to proceed after this interaction.

Before this chat she sent a picture obviously trying to look good (right angle and filter etc) wishing me a good night. This was after I sent her a selfie.

To me that makes me think she's interested, otherwise she wouldn't bother trying to send a pretty selfie after I sent her one. Right?

Do you guys think she means what she's saying? Is it possible she's just memeing or should I back off?

Thanks for your help either way!

Specifically I mean if A guy walked up to you, introduced himself, and gave you a compliment, and started a cordial conversation, asking for your number after.

I don't include guy friends here, because I assume if a girl and a guy are walking/sitting together that they're dating and that I shouldn't approach.