Hi and welcome.
I think Casey pretty much nailed it. It's all going to start with the size tank you plan on putting up. Then it becomes what you want to keep. The size of the tank also plays a part in what you can and can't keep as well.
With small tanks, 5-30 gallons, things happen much faster because there's less water. But at the same time they're easier to correct as one big water change is much easier to preform. These smaller setups are less expensive to start up but they can be very unforgiving initially until you get a feel for the feeding & maintenance.
Mid-sized, 40-90 gallon, would be a good place to start for someone completely new to saltwater but not wanting to spend the money needed to start up a large system, 110-220 gallons.
So, what were you thinking size wise when you decided you wanted something more exciting and what kind of budget have you set? From there it will be much easier to offer advise.