Many people use Fine Art America, but I don't recommend it. I tried it out, and the programming team is SO small, and the website development looks very out of date compared to others.

Another good resource: The Abundant Artist. Here's a current post about selling art, taking technology into account. https://theabundantartist.com/selling-art-future/ I would only disagree about NFTs -- not a great fit for most is my take.

I get emails from both https://www.callforentry.org/ (CaFE) and the similarly-named https://www.callforentries.com/category/art, known as C4E.

Another favorite trick of mine is to deconstruct other artists' resumés. If I find someone who's about the same as me, or a little further along, I scan their CV for clues.