how do i install carpet properly?

Honest answer: the tools are what make it doable. You need a knee kicker and, for anything bigger than a closet, a power stretcher. Both rent cheaply. Tack strip goes around the edge with a small gap to the wall, pad laid inside the strips and stapled, seams joined with seam tape and a seaming iron. Hook the carpet onto the strip on one wall, then power stretch toward the opposite walls, trim, and tuck the edge down behind the strip. Skip the power stretcher and it'll look fine for a few months, then ripple.