Upgrading Armor?

This is my first time playing the game and I've been doing quite well getting armor from looting. I am curious to know if there is any other way though?

I'd ideally like to have more control over the look and abilities that armour can offer, but if it's not possible, that's fine too.

I'm all about customization and would love to make my whole group look fly as heck.

Just to note: I'm an Xbox player, idk if this changes anything & I'm not interested in turning mods on in my first play through.