Yeah why not. I'm 22 and I do IT work for a living.....but I do little odd jobs on the weekends and after hours. Cash only....and I usually charge $20 if they bring it to me and $40 if I have to go there.
Works out good. Last week I did a small network for a lady I use to work with.......she got a good deal. It would have cost her about $75 an hour to hire a "Pro" but I did it in about 1 1/2 hours.......made $40.
I also have a computer sitting at home I'm working on........$20
You can do it and it will help with your skills.....the main reason I do it is to keep me fresh on this stuff. My network here at work is like a rock so I do not get too much practice.
Good luck.