While wearing this ring, you can turn invisible as an action. Anything you are wearing or carrying is invisible with you. You remain invisible until the ring is removed, until you attack or cast a spell, or until you use a bonus action to become visible again.
RollQuest ships the D&D 2014 SRD as a content pack, on a 5e character sheet that does the maths - roll from the sheet and let the numbers work themselves out. Free to start.