Your lack of familiarity with DMing 5e makes you an excellent candidate for this. The main selling point for this was that DMs could get in some DM practice with a player, so this is a good chance for you to familiarize yourself. As for what I want, I was thinking maybe the standard 'high adventure in a world of magic and wonder' affair would be a good idea. But if you'd prefer our game taking place under different circumstances, I'm sure we can agree on something.