Welcome! My first cast iron saw was one of these, or very similar. First thing you want to do is get the table top smooth and protected.
Unless there's heavy rust, I'd just use some 400 grit by hand in long, straight motions from the very front to all the way back, using as even pressure as possible. Try not to swirl, go side to side, or go nuts on one spot. You'll almost immediately feel the effectiveness of the sandpaper fade, so change hand positions on the paper to get all the life you can out of it. You'll probably go through a couple of sheets, either way. The goal should be just to get the table clean enough so that it's not transferring rust to the wood, and smooth enough to let to wood glide as effortlessly as possible. It's debatable whether or not it's worth it to remove all evidence that there was ever rust on the top. It's up to you, but be weary that the more you sand, the more material you're removing from the top of the table.
Protectants only last so long, so you'll have to make a habit of reapplying either wax or some sort of spray on. Wax is cheap, but it takes more effort to apply. It's easy to get too much wax. With too much wax, it's effectiveness as a friction reducer is gone. In fact, it's more difficult to slide wood across when there's too much wax built up.
Spreader? Maybe you mean splitter. Before you get a splitter, you need to get a zero clearance throat plate(hit up google to see what it is and why you need one). Whether or not you buy or make a zero clearance throat plate, Google "micro jig splitter". They make a different size for a few different blade widths(or kerfs). Speaking of blades, what kind of blade is on the saw right now? Before you get zero clearance plates and splitters, you have some saw blade exploration to do.
Obviously you know the saw runs, or you wouldn't have bought it. How smoothly does it run? If there's excessive vibration, a lot of people like to switch to the link belts. Just google "table saw link belt."
