Know your tonearm mass to start.
Buy a few set up tools to help you dial in the cartridges. I cannot stress this enough. I've been doing his a while and am amazed by how much of a difference this makes with better cartridges.
Pick a any brand and compare carts within an affordable (to you) line.
Try the different stylus shapes: elliptical, microline, shibata etc.. Avoid conical unless it's the Denon 103.
Try to compare a couple of carts at a time to see what you like.
Enjoy the ride.
I started with Grado, then Ortofon, Denon and now playing with Audio Technica. I'm also just starting my ride.