Plan to need to adjust your plans. Take your vitamins. Set aside at LEAST 30 minutes a day for JUST you. Start an exercise program now and stick with it. Designate your own mentor (not one that was assigned to you) who is a positive person. Avoid the people who do little else but complain.
The teacher's lounge is a gateway to hell. STAY OUT OF THERE!
Go to any and all professional development offered during the year. Sit near the front, ask questions, take notes. Sort through what is usable and what is nonsense and choose something to try.
Don't try to do everything you learned in college/teacher prep programs, etc. during the first year. It simply isn't feasible.
When something isn't working, change it!
Never, EVER say anything derogatory to a student. Your words of encouragement may be the only ones they hear all day.
Decide ASAP what your rules and procedures will be. Learn them, know them, and know how you will react when someone 'forgets' to follow them.
I recommend Harry Wong's "The First Days of School". Read it now, then read it again in a few weeks. Read it a third time before school starts, then keep it on your bookshelf as a guide. When things aren't working, it is a great source of ideas.
Continue posting here at TF. There has never been and will never be a better group of teachers to talk to than there is here!