To start - make sure you have connected your address to your account via "settings" on the top of your profile.
No tokens: If you don't see your tokens you own - you can add a token manually by entering the contract address of the NFTs.
Domains: If you have Unstoppable Domains (.ZIL) in your wallet - you can press scan for domains and it will load up to 30 of your domains.
(If have more than 30, we can only show 30, so they won't be displayed until you list some for sale and then the next few will be loaded.)
Once you have your tokens loaded - you can choose to transfer them to another address or sell them on the marketplace.
Transfering: See how to transfer my tokens.
Selling: See how to sell my item