I'm new as well (four months with my tank but a couple years on here reading). Right now I'm a fish only tank. Keeping saltwater fish is not much different than keeping freshwater fish. As long as you can mix the salt correctly you'll be fine. Fish aren't as particular about lighting and water parameters (calcium, etc.) like coral are. Just make sure you know what the fish need to thrive, acclimate correctly (to temp and salinity) and keep up with water changes and water top-offs and you'll be fine. I think a lot of people new to the hobby (me included) get lost in the details of what corals need. It's not as difficult for fish. What you do need a plan for is the type of coral you eventually want to keep to ensure you don't buy fish that like to snack on them.It will be FOWLR for me at first until the tank is established and I know a bit more. I have had a lot of freshwater time, but coming up to speed on saltwater has proven quite difficult. All in time.