I thought I was the only one to do stupid things and have bad first days!!
I get so stressed starting anything new, finding my way around, meeting new people, trying to sound OK when you are really freaking out about it all.
I started somewhere today and got lost in the building for a while and then got stuck in an elevator and ended up being quite late.

But if the first day was so horrible, the rest of the semester can only get better.
second days are always soooooo much better. I hope yours is.
And don't over extend yourself. If you can manage orchestra and enjoy it - go for it. But if it is causing your studies to suffer, maybe not so great. But since today was just the first, busy day, I'd give it a week or 2 and then decide.

PS the buses over here are bad to. they are always late, that is if they even turn up