NFTs are a scam. You dont even own the actual artwork. What you own is a digital record that contains a link to the jpeg or whatever is on the blockchain at that address (it could be anything really... jpeg, a music file, whatever.).
There are a few markets that are used to buy and sell NFTs. I think the most popular is OpenSea but I havent paid attention to this stuff for a while now. When you think NFT at this point in the new internet just think pump and dump scheme. Popular social people will pump up NFTs like they are the greatest thing ever to get people to buy them for mass amounts of money and then they just abandon the project making them worthless.