I was one of those horrible kids you're teaching now, but I was probably worse. I never assaulted a teacher, though: that wouldn't have been okay for me. But, belittling you, goading you, provoking you --fun. Especially if you're young, new, seem unsure of yourself, straight out of training, etc. Such fun to watch you lose control. Even funnier if you start crying.
Why did I, personally, behave like this?
power and control. I had none in my own life, and so I'd take it wherever I could find it.
I had a seriously shitty home life and all the adults I knew I couldn't trust, didn't respect, and I had to fight. As a teacher, you're just some faceless no-mark, and you have no higher value to me than any other person I encounter.
The idea that, as a teacher, you're worth more respect than anyone else in my life, would've been laughable. Respect is earned. It's not some automatic right. Teacher or not.
My top tip? Take the individuals that bother you the most, outside, individually. Tell them, calmly, that you're not happy with their behaviour towards you, and ask them if there's a problem in their home life and if they need extra support. That just takes the wind right out of their sails.
calling them out on their behaviour, in front of everyone else, puts them on the backfoot. They don't want to lose the respect of their peers, and so they'll escalate the drama so they don't lose face.
you'd be surprised how many of the kids don't see you as a person: you're just another authority figure, and if you came on to me all authoritarian, I'd make your life a misery. I'd probably steal your keys and lock you in the classroom. Daily. Until you got the message.
my second tip would be... get the ringleader to help you with tasks. Handing out books, collecting essays, running errands, writing on the board, etc, etc. You'd be surprised how much difference it can make for a 'bad' kid to be given some responsibility, to be brought into the school fold instead of excluded from it, to be seen as helpful rather than a problem.
hope it all works out for you, Werkinggirl.