Slow beginnings are good
I'll list the basics you can research what they do
Skimmer, rated for twice your water volume is the rule of thumb$
Lights depend on what you plan on keeping. The most commonly used lights in combination or along are Metal Halides, T5ho, Power Compacts, Vho/T12s, LED, you really have to decide what suits your needs.
Sump/Refugium there are several ways to go here but there again you have to research to see what fits your application.
Return Pumps and Skimmer pumps, Danner or supreme mag drive pumps are popular, reliable, and affordable. There are a lot of pumps manufactures to suit many applications. "Research"
Heaters of course
Refractometer
Sulifert test kits
Rodi unit with Tds meters.
Well that is some of the basic equipment, the type and brands are really up to you.
The best advice I can give you is research and buy quality equipment, there is a lot of junk on the market so before buying big ticket items check all sources for reviews and opinions. This is an expensive hobby and you don't want to be buying twice.
Enjoy