Expect to work harder than you ever imagined possible. It will get easier, but your first year will be extremely hard... everything takes longer when it's new....marking, planning, preparation etc.
Be organised. Get a folder with those plastic wallets built in- you will be handed hundreds of slips of paper in the first few days and you will need them all! Logins for various systems, list of pupil premium kids, key dates (different versions from your department/year group/house).
Look at exercise books from your new department... reading the marking policy is great but it's useful to see what they think good marking looks like in reality.
Find out what topics you are teaching and start swatting up on your subject knowledge...no matter how much you think you know, there's always something new.
Network through social media...there are some cracking groups on Facebook to join, have a search for your subject/area/keystage.
When it comes to behaviour management, remember you catch more flies with honey! "Will you tuck your shirt in for me?" with a cheery smile and enthusiastic thanks is much more likely to get compliance than, "sort that uniform out now!". That said, be firm. Follow up on everything. Follow the school's behaviour policy to the letter, while being smiley and nice. That way kids know they won't get away with anything, but you'll build good relationships because they'll see that you're nice.
Sorry if that's rambly. I'll see what else I can think of.
Good luck!