You should be able to keep soft corals and many if not most large polyp stonies depending on placement.
Soft corals are the easiest:Mushrooms,Kenyas,Colt,Green Star Polyps(GSP),leather corals like Toadstools,Devils Hand,Thin Fingers make some of the easiest corals to keep
**I would let your tank mature a little longer for Xenias...either they grow like weeds in some peoples tanks or die mysteriously.**
LPS wise,Hammers,Frogspawns,Bubbles and Torches,a little more light demanding and feeding but still fairly easy.
The best placement is LPS top half and softies bottom half,this is just a guideline,there are exceptions to the rule.Good luck on your first corals.