Hello! Posts that may be useful for DADA FAQs:
https://steemit.com/dada/@dadanyc/how-to-buy-rare-digital-art-on-dada
and their medium blog:
https://medium.com/@PowerDada/dada-faqs-e5372184f8ed
You can't currently upload work to DADA - it is all drawn on their site and currently they are only selling a selection of work in the art gallery part of the site.

A couple of sites that may be of interest for uploading work are SuperRare and KnownOrigin.io

Super Rare has a good explanation of crypto art: https://superrare.co/about