Having an internship or paid job shows colleges that you have real-life skills that you will need after graduation. If you are self-employed, it also shows initiative and entrepreneurship. If your family cannot pay entirely for college, a job will also help you have less debt.
Snagajob.com is a good place to look for part-time work. If you can't find a good job, make one yourself! You can babysit, mow lawns, etc.