Need some advice on my 2 kids...?

So I have two children. A two year old girl and a three (almost four) year old boy. I have tried every method of discipline I can think of.(taking away toys, timeout, positive reinforcement, spanking, early bed time, no snacks, etc.) Both of them refuse to listen to anyone. They destroy my house. My son seems like he has so much energy that it is mind baffling, he also does not focus. He is a very smart child, he knows big words thata child his age should not know... and yes he understands them and uses them in proper context, yet I can not get him to sit still to learn his abc or 123's its like he can't focus. He goes into "his own little world". Both kids do not listing to anyone about anything. I don't want smart a** remarks saying I am a bad parent. Cause I'm not. I just want some advice on how to deal with the situation because I am a seriously concerned mother. So if your gonna post some snide remark don't even bother posting at all. Thanks.