Hi and WELCOME to AA
A good place to start is by reading this thread
< click there. Then go the articles section and read about the fishless method of cycling a tank.
Come back and start posting questions in the Saltwater & Reef - Getting Started
section. There are many here who started the same way. I had a fw
tank(s) for 10+ years, and then went without one for a few before deciding to take thw sw
GO SLOW is the best advice I can give you 'cause "nothing good ever happens fast in a sw