my sorority is weird

I would say you've still only met a handful of them so stick it out, have a good attitude and give it a chance! Meet up with girls in your pledge class. Try to get to know as many girls as you can. You are not going to vibe with everyone in any group.
You also are "out" until next fall anyways so may as well give it a go!

Give it a little more time and try and meet as many girls as you can. It hasn’t even been a week.

It’s only been 1 week, give it time. This happens every year, this week is super busy with their new classes and getting into the rhythm of school. Not to mention the delta variant is getting a lot of people so a lot of girls probably can’t hang right now. It’s only been 1 week and there’s no way you can know everyone, let alone your PC well enough to decide if you wanna stay or not. Give it some time and actually try reaching out to other girls you may have only said hey to but haven’t actually talked to yet