Idk what’s my problem

Term break is finally here and some girls I know who are from grades slightly younger than me are inviting me to the outing they’re planning. Trust me when I say that these girls are nice people to be around but I just feel…out of place. I’m one of the oldest in the group with me being almost 16 and the rest are around 13-15 (keep in mind that my school is very small) which I know probably isn’t that much of a difference + I have online friends around that age so what’s the problem. I can relate to them about certain things but I’m also completely different in terms of my interests and my maturity. Small talk can be nice but sometimes I want to look for something more which is hard for me because I only open up to very specific and certain people which in this case is not them. I’m also not really close with some of these girls, I see some of them in the halls and it’s nice to smile at them but it feels like we’re nothing more than that. I feel like I’m forcing myself to go on this outing to fulfill that lack of social interaction I have. Sure I’ll probably still have fun sonehow but that only lasts so long. Once I’m back home I’m just me again, the loser who goes out every once in a while. I wish I had a friend who was like me, all I’ve ever from an outing is to go to this old mall and check out all the record stores in it but I don’t know anybody who likes physical media and even if I did I’m not really close with them. Sigh this sucks