If you talk to an Enchanter NPC, the option to enchant will be in the dialogue list like a shop owner or spell crafter. Since you’re in the Mages Guild, the easiest to reach would probably be Galbedir in the Balmora Mages Guild.
If you need more specific info the UESP wiki (en.uesp.net/wiki/Main_Page) is a great source. Just be weary of spoilers. I personally use it to check racial attribute spreads whenever I start a new game.