About to start my first year teaching... hELP!!!

Hi reddit, I am about to start my first year teaching at a small private Catholic School. Here's a little about me, I just graduated from college with a degree in Biochemistry and minored in Education. I was a four-year athlete and held many jobs from interning for a Dean, academic advising and being a teacher's assistant. I have been a Head Swim Coach for the last couple summers and have a great rapport with children.

I just got offered a position as a middle school science teacher today. School is clearly around the corner and I am starting to feel a little overwhelmed with relocating to a new city and teaching. Luckily, the headmaster seems like a great guy and ready to support me and the class sizes are small.

Does anybody have any tips for my first year of teaching? I am really outgoing and excited but could use someone to give me some advice on what I may experience.

Thanks in advance!