How to activate gold weapons? Also what are gold keys for?

Help?? I don’t know how to do this…

The gold weapons thing from the rewards are actually skins that you can apply to a weapon. Select a weapon in your inventory, inspect it, and look for additional options.

Gold keys let you use the Golden Chest on-board Sanctuary (down on the lower decks near Earl’s and the Cargo Bay iirc.) Using the chest costs 1 key, and yields random loot of purple or better rarity at your character level. I spent my first one the other day and got something like 6-8 purple rarity pistols. Item type is random - could be any gear type.