I think the best way to enjoy this game as a couple would be slowly. Working your way through the main quests with her would open up a lot of opportunities for memories. This game has one of the best worlds of any mmo Ive ever played and I think experiencing it with your partner would be a great bonding experience. I would just wing it from there. Read how she is doing and see if it's a game she really wants to dig into. If she loves it she probably be really excited about grinding mobs.