How do you enable a background? When I try I can't see my HA.

Click on the background to the left of your HA preview in the wardrobe and drag it below your base layer

I'm confused. None of that works in my wardrobe. All items are on the right and when I try to drag items it doesn't work.

What browser are you using? There should be a list of all the items you're wearing to the left of your HA, those are draggable and used for relayering items on top of/underneath each other

Google chrome I Figured out what you meant! I clicked and dragged the boat to the bottom of the list.