Hi, welcome first of all. Before jumping the gun and putting fish in, it is a good idea to make sure your tank is ready for fish. Posting on a forum is a great way to start
So how old is the tank? What are your nitrates, nitrites, and ammonia levels at? What are your plans for the tank? (Reef, fish only, do you plan on putting inverts?) Keeping good upkeep of your tank is one of the main keys of keeping your pets alive.
That being said, clown fish are usually the staple of a reef lol. They are usually what everyone enjoys and recognizes. I would advise against damsel fish, usually they are extremely hardy fish and very cheap, but they grow big and mean on the norm.
If you are looking to an alternative to clown fish, maybe some cardinal fish or blue/green chromis. The idea is to keep these guys alive and with you while your reef lives on