Many newbies ask this question: my answer is “as soon as you can”.
Seriously, there’s absolutely no reason to delay. If you’re still living with your parents, that’s the best situation ever.
Later if you go living on your own, you’ll realize how easy is to waste whole morning or afternoons for “trivial tasks” like going to town, cleaning the house, etc.
So if you aren’t engaged, live with your parents, I’d say it’s the ideal situation to start your indie business!