Learning to skateboard? got a cheap one?

k, i wanted to learn to skateboard so i went to target and got a double kick skateboard. by the way, what the heck is a double kick?! i tried to stand on it and move around and the the board wobbles or goes side to side whatever you want to call it. why does it do that? is it normal? since i'm a beginner is that alright? or what do i have to do??? please help!!!