Clownfish are a perfect starter fish. They seem to live through anything. Or if you want to have some really hardy fish start with some damsels.
Inverts would be harder to care for because they usually have more specialized needs. Other than hermit crabs you usually have to check your calcium levels and all that good stuff.
Like tripper said 2 fish would be good but i usually go for one extra lol.
I have a 10 gallon sw
tank with one scooter dragonet,1 false percula clownfish,2 hermit crabs,and one banded reef shrimp.Im planning on some more things as soon as I get a bigger tank.But i would just start off with 2 if this is your first tank.