What are the dimensions? What are your goals for the tank? How much cover is available in the tank?
There's always the classic clownfish situation, and shrimp gobies+their pistols are rising in popularity.
I think you could probably go with a dwarf angel of some sort. A lot of people want the "tang" look, so I think that a lemonpeel angel would usually make a good yellow tang substitute.
I'd honestly also recommend looking into buying a protein skimmer. You don't really know what you're missing out on, until you don't have one.