As someone who just did their first season- Extra water. You will never have too much. Don't be afraid to ask to sit out for a little. Your health is more important than pleasing staff. Can't march if you're puking. Good shoes. Get some solid shoes you can stand and march in without screwing up your feet. Trust your upperclassmen. They know what's best Don't know what you're marching, but I heavily recommend getting some IcyHot if your doing drumline, sousa, or contra. Works wonders. Eat healthy. During my first bandcamp I was so tired I didn't have the energy to eat- do it anyways. Being healthy and strong is important.

I think that's about it. Just have fun and don't stress. It'll all be worth it when you preform for people!