Well this is an ambiguously question. Depending in your individual situation. I think the overriding wisdom is that if you want to be a freelancer then you should start right away.

Are you sick of working for other people and are you really good at what you do? if you can answer yes to those then yes, you really should start freelancing. Of course you can't quit your day job until you're sure it will work.

When someone hires you as a freelancer.

I think first you should try to become a part-time freelancer, you can get some experience from that, and when anytime you think you have the ability and experience to be a full-time freelancer, just do it.