How can I purchase a home when I live paycheck to paycheck?

I can't go back to school, with 3 young children, a job and no help from there father. How am I suppose to make a good life for us when I can barely make it through the week? I do not have the best of credit. Even if the home is a fixer upper it would be great. I could work on it during any free time I have. The thirft store here always have windows, door, appliances, sinks, toilets, etc. really cheap. I have family that does construction that would let me have scrap lumber from the jobs I could use. I know I maybe able to get a owner finance but I don't have the $2000 down payment. Paying the monthly payment wouldn't be the problem.