Stay in the job. Start your side business on your downtime. It's NOT easy doing a home business, and there's no regular income - you'll be freaking out when you can't make rent, buy food or do anything because the money just isn't coming in.
Figure out FIRST where you're going to sell your art, what are the fees on the sites, which sites are you going to use. Will you find enough customers to buy your stuff, will they KEEP buying, if you don't get repeat customers you're going to make less money.
Your 'schedule' isn't going to be yours to choose if you work on consignment. You're going to have dead months where no income comes in. Look, you have a kid, keep to the steady job and build up your side business till it's reliable and able to actually support you on a yearly basis. I've been doing my art for 18+ years, It's barely able to support me. I have at least 4 other people taking my art to events or buying it wholesale to resell on their sites, I sell online and I do a few shows a year that are local. I'm online. What's selling varies all over the board and changes with the seasons, but no matter how much I try I can't get past the $10,000 a year mark here in the Midwest. That's total sales, the profit drops down because I have to buy supplies to do the work. My profit is less than half that so I have to do part time office work locally. I'm considered 'successful' since I've not had my sales intake drop below my cost output for more than one year out of all those.
The artists I know all do it either part time, as a side business, or are constantly looking for freelance work that is generally not satisfying because of the needs of the customer trumping what the artist wants to actually do themself.