Can I find a way online to do my budget with the amount of money I have to work with.?

I have 1600.00 dollars a month to work with. Rent, phone, and light total about 700.00. I have medical bills for about 3,000.00 that want their money now. Add food, gas, miscellaneous. Plus I want to be able to save a little each week. But how can I do this?