Did it not come with instructions?
Here's how it works. The outfeed table (furthest from you) should be at the same height as the tips of the cutters when they are at the top of their rotation. It may or may NOT be adjustable, depends on the jointer design. IT's not easy to adjust the knives to the same height as the outfeed table for a beginner. There are videos on how it's done.
The infeed table (closest to you), is fully adjustable for height BECAUSE it determines the depth of cut, much like a table saw blades raises up or down, depending on the depth of cut. NOTHING will happen if you raise the infeed table to the top of it's travel, NOTHING.
You will lower it gradually to take more material off the workpiece, usually about 1/32" inch at a time. If you try and take too much off at once, the jounter doesn't have enough power and will stall out.
Go on You Tune and watch the videos on the USE of a jointer and the SETUP of the jointer. Then come back with your questions.
The fence should be square or 90 degrees to the top of the table, nothing else matters. It can be at a slight angle, when looking down at the top, but that doesn't matter. Take a square and place it on the top of the table. Run it across until it bumps the fence. There should be no gap when they meet. This is also adjustable depending on the the design of the fence. Read the manual or show us photos.