I'm going to high school in less than a month. One day back while I was in 8th grade I had to go there to take my placement exams. The seniors are incredibly nice. There's this program at my high school that lets seniors help the freshman. They are very kind and welcoming. Only the seniors were there. It was a little bit crowded. My high school in total has about 4000+ kids so it can get pretty tight. We have 10 floors though so it won't be a big of an issue.
Alas, I made no friends. I was only there for one day I don't think I could have lol. Well good luck in your high school.