There are many ways to earn money from arts as the world arts is really large and broad.
Firstly,you can make money from arts by drawing images like images or an expression of something either events, festival or beliefs. Many people may love the image you drew and may pay to get some of the images which will in turn generate revenue or profits for you.
Secondly, you can make money from arts by making some art materials and selling them. Art materials like basket, mats, clothes and many more which may attract patronage which will definitely also brings revenue or profits for you.
There are many more ways to make money in arts but I guess I knew of this two major ways to make money in arts and I hope it helps you.
Well, you did not tell what kind of art, on which level, etc. There are many possibilities. You could sell your art online via Ebay or Etsy. You can make a homepage for your art and promote it via Steemit, Facebook, Twitter, Instagram, Pinterest. If you talk about paintings you could try and find a gallery who is willing to make a vernissage and subsequently find collectors for your work. You could exhibit and sell on artfairs, art markets, etc.