best friends brother

So, my best friend has an older brother who I just recently met, as he has been away at college (maybe 30 min from our town). While it's not too far, he really doesn't come back and forth much. I found myself hanging around their house much more often when he was in town, and making sure I looked cute to go over, etc. My friend kept telling me how alike we are and how we'd be good together. Their family loves me too so they wouldn't care. I don't even know him all that well, but from the moment I met him, I just felt this super strange connection to him... I just enjoyed his company so much. My friend says he asks about me a lot, too. He told her I look older than 17😂 The only problem is, he's 20 and I'm ....17. It just seems a little off right now because he's in college and I'm still in high school. But, I do take a few classes at the college he attends! And I just found out that I have a class in the hall that he is always in. What do I say if I see him? Should I even bother pursuing this right now because of the age thing, or should I wait it out? 
UPDATE:
I haven't really seen him much since this post, as he's been at school. I saw him on easter and he took a pic for me, when I questioned his angle he said, "you look good, trust me" 😍 But tonight I went to my friends house and he was there. He was near me pretty much the whole time and I could see him watching me every time I talked to someone. Then we decided to play a game with the whole family. He sat right next to me! Our legs touched and he said sorry, but then they kept touching and he stopped saying sorry and moving his leg away😂 every time something funny would happen, we'd look at eachother and laugh! I accidentally helped him win the game and his dad goes, "oh I could've seen that coming, I knew you'd help him" and I think my friend was kind of noticing us laughing together and making jokes. I'm usually not like this with guys at all, it's so weird that I'm so excited about him!! I just love being around him😊 I won't see him again until prom or graduation, but I can't wait til then! I also decided not to go after it now as spending time w my friends is most important right now, as they go off to college. He's also going to go active duty in the army after he graduates in a year or two, so I don't know what to do. Not to mention my parents wouldn't be cool with it and nor would his. I think it might just have to be one of those things that happens down the road. For now, I'm just happy seeing him when I can!