Hi Kim, there is some good advice already above, I recommend doing this well from the start on Facebook in particular, I have built pages and manage 5 regularly, it can be a real nightmare if you don’t set it up well and then have to switch once you have a following. Instagram could also be amazing for selling beautiful art, its a very pictorial based platform, as is Pinterest. With social it is always good to know where your audience will find you, where they hang out, what they like to watch and see. Once you identify who your audience is and some of their browsing and buying behaviors then you can put your energy into reaching them through the platforms they like to hang on.
People may be ‘on’ Facebook, but are they looking for what you have there? That is the key question.
There is a bit of Psychology behind peoples behaviors in this space.
Your website will be important as a browsing and purchasing tool. I agree there are some amazing template sites out there that don’t cost a bomb to create, maintain and use, WIX, Squarespace and yes Shopify are all good.
Work out what features you want your customers to have because ultimately everything you do has to be about them, what they like, their preferences and user experience.
If you make it easy for them to understand what you offer, find you and purchase then you are winning a big part of the battel
I hope my additional comments have helped.
As a marketing expert I often see people put stuff up and out ‘there’ without giving through to that planning part of the foundation, understanding the audience and objective.
Happy to answer any questions you may have on this if you want to unpack further
Good luck