Starting up is not that difficult for fish only, but fish and anemones are two totally different things. Anemones are very difficult to keep alive because they require special lighting (not too much or too little); feeding and feeding frequency; currents; care to prevent injury from powerheads or the wrong tankmates and even substrate, etc. A clownfish in a tank can thrive without an anemone, but an anemone in a tank will most likely die.
As for starting up a fish only tank, you can start it like a freshwater with general filtration- just add a good salt - and be sure to CYCLE it like any any other tank before adding to the bio load. Good fish for that are the most common damsels (tough as goldfish); pH, ammonia, nitrate; nitrite, alkalinity testing (MARINE test kits, the ph one will be higher, too). Water changes; when you remove water replace it with an equal amount os salt water; add FRESH water to replace evaporation (salt does'nt evaporate); and above all, PATIENCE. Give it a good 6 months.