although this should be in the saltwater questions forums i will answer it anyways.
i suggest you buy a book, especaily if its your first saltwater tank. the best book i know of it called "The Simple Guide to Marine Aquariums" by Jeffrey Kurtz. this book has everything you need to know.
since this is your first saltwater tank and you want a fish only tank i would suggest you go down one of two routes.
route one- stock your tank with a community style of fishes.
example-5 or 6 green chromis, 1 royal gramma, 1 maroon clownfish, and either 1 flame angelfish (a very pretty and hardy fish that is overlooked sometimes) or a niger/black triggerfish.
route two-stock your tank with a few larger species.
example 1- 1 trigger fish and 1 eel (i suggest a snowflake since they are also hardy).
example 2- 2 lion fish, maybe a tailbar (Pterois radiata) and a dwarf (cant find the scientific name...)
example 3- one grouper or one snapper. the only problem with this is you will either have to find a good hardy grouper that wont out grow your tank or plan on buying a larger (100gal or more) tank down the road, but that will be maybe 4 or 5 years down the road.
i would get reading some books if you are set on saltwater
