That very question may haunt you for a long time!
You may need to be a little bit more specific as to what you plan to try to keep. There are tons of coral possibilities out there and a simple answer to the question would be impossible.
Your lighting, filtration, bio-load, water chemistry, water current, etc.. will all play another part in the corals that you can keep.
You are starting out good doing research, but you might have to get the questions narrowed down a little bit.
Good luck and.............