Flame Angel

So I jump the ship and decided to get a flame angel for my 75 g tank that only has 3 fishes , paid $50 it is an adult and my fears are kicking in, went straight to hiding , hasn't eaten I offered brine shrimp with garlic concentrated , and nothing. My other fish and fish that I have had in the past they eat at the first feeding and thrive, but now that I paid a fair amount of cash I'm going paranoid of loosing it