Hello people, im new in here!

So I'm having a trouble about lucid dreaming. I experienced Lucid Dreaming only one time but im trying. Whenever im dreaming weird stuff starts to going around. (as usual in a dream :p) Like my maths teacher kicks poor people or homeless guys and stuff like that. As soon i realize its a dream, guess what. I wake up? Why is that happening? And what can i do for it?

Thank you for reading!