First off, Welcome to AquariumAdvice.com!!
I agree. Two clowns max, but only if they are a mated pair. Otherwise it is trouble. They are very agressive towards other clowns.
I need help with filtration, lights and so on.
That is a lot to cover in one post. I do suggest you get a good book on SW
tanks. I like "The Consceintious Marine Aquarist" by Robert Fenner. There are also articles on getting started in the "Articles" section at the top of the page.