Getting started it would much easier if you could just add your works to an existing site. In the photography world there are many such sites. Some of these sites even allow you to link from your own site.
If you do a web search for say "buy art online from artist" it may turn up some prospects.
Like this
Art gallery, sell art free, art community for artists | Foundmyself. Any prospects would need to be checked out before signing up.