Lets talk about how you can create your own NFT.
Now remember there are manypre-existing things that can be converted to an NFT (like art and music) and many things that can be created for the first time (art, music, graphics, almost anything)
So make sure you spend some time on OpenSea looking at what other NFTs look like and how much they charge.
If you have some digital art experience that is certainly going to help you here.
Most of the digital art pieces would be created or altered in programs like Photoshop or Gimp or others.
You may want to create a collection of NFTs to sell which could be 50 or 5,000 slightly different looking images.
You may have a hairy monkey with green hair and one with purple hair and then 30 of them wearing different hats and another 50 with different colored shirts and on and on.
Vector based programs are best because they allow you to create the layers of images that you need.
(under construction Dec 16, 2021)