Hi there. You can't purchase actual armor or weapons from Eververse. Those are actually Ornaments, which are basically like skins for other gear. First, legendary armor Ornaments are universal, so they can be equipped on any legendary armor 2.0 (essentially all legendary armor that wasn't pulled from your Collections). Exotic Ornaments, however, can only be equipped on the specific exotic armor/weapon that it's for—similarly with legendary weapon Ornaments. If you bought a set of Universal Ornaments, you need to open the Eververse bundle located in the Wrapped Items section of your inventory, which then put the Ornaments in the Modifications section where you can unlock them. Then, to equip them, inspect your legendary armor 2.0, tab down to the Appearance menu, and select the Ornament from the customization slot.

Eververse does not sell any armor, but armor ornaments instead. You'll need to go to your armor's appearance settings and choose the ornament to apply it.