Age, art style, etc. have nothing to do with it. There's someone who does stick figures with stupid jokes, and they're really popular and enjoy what they're doing. Having a good time is the important one, by the way.

What's important is if you want to. Don't start a comic just because it looks cool or other people are succesful, start it because you came up with an idea you really like drawing/writing and want to continue on. Or start a comic because you doodle that stuff during class anyways.