I'm a junior in highschool and I never really had much trouble tbh. What I did was just be a generally nice person to everyone and talk with confidence even though I wasn't. Most of the time the stutter itself isn't holding you back it's the way you go about it. So try to be as extrovert as you can, I'm an introvert myself but for those first few days I push myself to go and talk to new people. I'm my experience my classmates don't care as long as you're not a doucuebag. I did already have a friend or two everytime I got into a new class wich helped me fit in more so it might be different if you don't have a friend already. In my case though people didn't even notice for the first few days and when they did they thought I was nice enough to not mention it/not care so if you're just a good person and be at least a little talkative occasionally your stutter shouldn't really hold you back much.