How do you deal withe grade 8 students who won't behave for you and should it be taken personally?

I am a grade eight teacher. I teach rotary social studies and math. But my cles are all pretty misbehaved. I have some cles that are better than others and it is an inner city school, however, I feel that I am kind and give them lots of opportunities to pull up their marks but somehow, they don't pay attention in cl, they talk all the time and for no reason at all, they don't respect me. I know that I look young for my age and I am a white female when most of the student body are somalians and East Indians, however how do I get them to behave without going soft and then going too strict and should I take it personally that they say mean things to me and don't do their work?