what is the best way of handling a class?

Zup, Yan! Hey just loosen up a bit. Don't be the terror like teacher. Students hate serious-looking teacher. It bores them that's why they diverted their attention to other things.

What do you mean by "crazy fonded" student? I suggest you try to be relax and don't be too serious. If you get angry most of the time because of your students attitudes, you'll be exhausted too early. Take life easy and laugh with your students. Attend a Baptist Church and observe how the preacher handles himself and hold his audience. Learn from it, it will greatly help you!