In a nutshell I’d say to do this.
Get a larger tank. I started with a 16 gallon had buyers regret and purchased a 30 gallon which is the bare minimum I think a newbie should start at.
Get a decent light. You don’t have to break the the bank to do this. AI Prime series is good, so is Noopspych, and I believe Kessils are relatively inexpensive. They’ll all grow corals of any type given the proper size tank. Get live rock for your tank , and I mean the stuff off the gulf coast/Florida . There are several vendors that are all good to use. Gulf Live Rock and Tampa Bay Saltwater would be my choices. For wavemakers I’d recommend Jebao as they’re reasonably priced and pretty reliable. Get decent test kits . I believe others have mentioned Salifert which make reliable test kits for a reasonable cost. There’s a couple Hanna test kits I use as well but do your research and figure what fits your budget as well as how well rated/reliable they are. Get a refractometer to check salt levels . Make sure that copper isn’t coming straight from the tap…
Beginners dosing. Get at a minimum a 2 part Alkilinity and Calcium dosing set up. Also Magnesium and Iodide are important.
NO CORALS for several weeks at least, then get hardier ones like leathers, mushrooms, zoas, and starter lps maybe like Duncans, Candy Cane or possibly even Micromussa. There’s more to pick from but this’ll give you a good starting point. You can probably put fish like clowns within a week or so , possibly sooner if you use all live rock(get 1- 2 lbs per gallon at least).
By the way I still have that 16 gallon except it’s a freshwater on my bedside table now.