Most artists who make a living with comics don't only do comics as their living. They also sell prints, merch, paintings, physical zines and books, they stream, do illustration for clients, and they sell at cons--the cons I think are where a bulk of the money comes in, but bear in mind the cons that make a lot of money are very hard to get into and cost a ton to go to so I'm not 100% on how that works out. I haven't sold at a major con myself.
Something to remember about freelancing (being an off and on freelancer myself) is that it takes a really long time to build up a following and a list of clients (and you have to HUNT for those clients, they won't come to you). I would consider checking out artists who write extensively on this subject (I recently came across Drawn+Drafted, which is a great recourse for beginners. The person who makes it has a twitter where they are always giving free tips on making an art business ((the drawn + drafted course costs money but they have free PDFs and free good advice))) Because what you are doing is building a brand from the ground up, the same way that an Etsy store selling soaps are building their brand. Branding your business is key, making a website, making a professional storefront, it takes a long time.
As for making money doing comics, it's the same as authors who make money doing books--you have to publish quite a few before you start seeing royalties, and doing webcomics means you never guaranteed any money at all. You're just living off of the mercy of the internet which is...more like waiting to win the lottery. So, you may want to start sending a comic portfolio to comic art directors and see if anyone bites. (this also requires that you make a website.)
A lot of comic artists also have a part time that is not art related. I always have a non-art related part time just to keep my own sanity, I highly, highly recommend doing that. Freelancing is very feast or famine.