Please help! >_

Hey guys! I'm Hannah, I'm 16 years old, and I've been suffering from severe social anxiety since I was 10, it's crippling, and because of this, I've been homeschooled my whole life. This year, I've decided to go to school, and it scares me shitless, school starts in less than 3 weeks and my anxiety and depression is going crazy. I'm terrified. I'm so, so, so socially awkward, I'm very bad with people, and even the slightest things like when people say hi, give me awful anxiety to the point of panic attacks. I overthink a lot, which I know is common. So can some of you please explain to me how school in the US works? <-- probs sounds super stupid >_<

alright, so, anyways, with the desk situation, what do I do? Where do I even sit on the first day? Do you just walk in and be like "waddup" and sit wherever or?

how the crap does PE work? Like what even do you do, ew,

when do you get textbooks and shiz?

what are things that are a necessity on the first day of school?