Search Results: i worry too much about my girlfriend

I'm a junior & I know this year is going to be stressful & tons of work. Last year, I fell for this guy in the popular crowd, but I'm pretty much over him now because we never really talked, we aren't in the same social group, & have no mutual friends. However, he was my first real crush & I've heard you never get over your first crush. I kind of feel like I need someone to fill the gap.
1) This year, there's a guy who's caught my eye & I'm pretty sure I've caught his eye too. We're in the same social group & I think we have some mutual friends. We've never talked or even been formally introduced, but my girl friend keeps encouraging me to talk to him. So, I think a relationship could actually be within reach if we put some effort into talking to each other.
2) There's also this senior in one of my classes who I think is cute. But after talking to a senior girl friend, I found out he hangs out with the wrong crowd so I decided not to have anything to do with him. I also learned he has a girlfriend. But last night we were both at an event (I was performing) & I looked up at the audience right into his eyes. He was staring at me kind of half-smiling & after we made eye contact I quickly looked away.
3) Very recently, I feel like I've caught the attention of a senior who was on the homecoming court (so he's popular). He's good-looking & seems like a sweet guy. We have one mutual friend who could introduce us, but I feel like this is a very similar situation as my crush last year. I don't want to get my hopes up that there could be some meaning to his glances, so I'm trying not to think about it.
I appreciate anyone who has read this far! If I had 1 phrase to describe each guy: 1 nerd, 2 smooth talker, 3 heart throb. I'm open to just becoming friends with (any of) these guys, too. Should I just focus on school & not worry about boyfriends? Go for the guy who's within reach? What do you make of the 2 senior guys & their frequent glances? Am I overthinking everything?