I retired two years ago Shaun, but 'Once a teacher, always a teacher'. Today, in the bank, I moved toward the first available cashier who said, "I'm sorry but I'm not serving no more." (Really!)
A moment later she emerged from the nether regions and spoke to me as she passed. I just couldn't help myself; I corrected her, in the nicest possible way, though I wouldn't have done it if I'd thought she'd be offended. (She knows me, and she wasn't.) She said she hated English at school, and laughed when I said I hoped she was OK at maths or I'd take my money elsewhere.
You'll get many, many tips from others so I'll just say this: Good luck in your career. It's a very rewarding occupation but it's not always a picnic! Start how you mean to go on, and don't take any nonsense from your students. (They will test you.)
...And be warned: you will never
totally cease being a teacher, no matter how old you are
Jayne