OK last Sunday I went ot my friends church I think this is the third time but I saw this guy at youth group and I thought he was really cute. I have never seen him before in my life and I know absolutely nothing about him but I want to somehow talk to him in the future how do I do that? I am a complete novice at this. Im 15 and almost all of my friends are girls. I have no idea how to talk to a guy at all and I'm absolutely terrified that it will be awkward. What should I do??

In my experience, talking to guys is a whole lot easier than talking to girls. I have about 3 girlfriends, the rest are dudes.
It will only be awkward if you make the conversation very mechanical, or, if you get stereotypical. You can't just walk up to a guy and try to strike up a conversation by saying, "So, what kind of video games do you like? What kind of sports do you play? etc." Some guys don't play video games and sports. Guys, just like girls, have different interests- don't automatically expect him to be obsessed with cars, or into competition just because he's a guy.
Just be casual- talk to him about everyday life stuff like school, friends, movies, etc. stuff that most everyone can relate to. Soon enough you will find something you have in common and things will start from that. I encourage you though, to not get emotionally involved with this guy- begin with a friendship, he may be cute, but he's just a dude- there are plenty out there, and you are a little young- Start by finding guys as friends, before you go off finding "guyfriends"