Most Helpful Girl
First off, there ain't nothing wrong with being an introvert. Introverts are awesome! :D I'm an introvert too!
There are definitely some challenges you will face, but extroverts have challenges too, everyone does! So don't feel bad.
The best way to move from being single to in a relationship is to get involved with activities. Grow your circle! It might seem scary, but trust me, if you start going out and meeting more people you will eventually find a girl.
If you join an activity group, it will be much easier to talk to someone you're interested in because you can talk about the activity. That can be your icebreaker.
Work on your conversation skills, gain confidence in talking with strangers. Basically it comes down to realizing that no one is better than anyone else. Once you realize that people are just as afraid of you as you are of them, then you can find some comfort in that (at least that worked for me).
Build up your conversation skills and gain some courage to talk to people.
After a while talking to people and joining in on activities becomes second nature. Plus there's the added benefit of making new friends and possibly even meeting someone.
Then once you've started to feel more comfortable try some online dating and also talking to people in bars and other places. Once you start to get better at these things you will start to have more success.
It might take a while, but the more you put yourself out there, the better your chances are!