What client are you using? Amethyst, Primal, Damus? That will determine you customizability.
Discussion
I have amethyst and primal set up.
In Amethyst, go to relays and simply use the default and recommended relays for now. You want to keep these to a minimum to decrease spam in your feed and comments, so I recommend default and maybe a couple more, but don't try to add every one you come across. It does more harm than good.