How do I make myself feel less insecure? DON'T READ ALL THE DESCRIPTION?

[Caroline]

I'm in 10th grade too, and I know exactly how you feel. I'm naturally pretty quiet and not very outgoing, and I started last year at a new high school where I didn't know anyone. Last year was pretty hard because I'm not good at making friends, but this year I'm in a similar situation to you, where there is a group of girls I'm somewhat friends with, but I'm not always invited to stuff they do, and I know they're all closer to each other than I am to most of them. So basically, I know what ur going through.

Something you should remember is that, even if it was as an afterthought, this girl invited you to the party, so she must like you and think you're fun/funny or something otherwise she wouldn't have invited you. What I've found is that sometimes people who you may not be like super close with actually really like you and want to get to know you better, so that might be the case with this girl.

It's definitely a good idea to become really close with one of them and build off of her. I've recently done that with one girl and she's now pretty much my best friend, she makes me feel more confident when I'm with her and the group because I can talk and joke with her easily and it just spreads to everyone

What I'd do if I were you is come up with a plan. Just sit down and think about each girl individually, this makes them seem less intimidating, and it's better to think about them as a bunch of individual girls, rather than one big group (does that make any sense?). So think about each of the girls, and try to figure out each one and her relationship with other girls in the group (like how many really close friends she has in the group etc). So basically go through each of the girls and find whichever one you think doesn't have like one best friend yet, maybe all of the people she's really close to are closer to someone else (again, not sure if I'm making any sense, sorry!)
Anyway, you mentioned it's hard for you to become really good friends with someone in a short period of time, just start talking to whichever girl you pick. You should try telling her a story, like in natural conversation but just be like "oh my god, so the other day..." And then tell her some funny story/ just something entertaining that happened to you (it doesn't even have to be true, just something that COULD have happened ) so then she'll feel like she knows you better, and might share something that happened to her and so on. I guess the hard part is making this happen where it seems like natural conversation :/

Also, you said you are pretty good friends with one of the girls already, but she likes to have a lot of close friends? Try to hang around her at the party, talk and laugh with her, that way you'll seem like you are a lot of fun and really part of the group.

Good luck! Hope this helps!