It is so easy to make money in the Sims. If you are starting in a house you won't have to worry about buying anything and even food comes free if you use the quick meal option from the fridge.
Even if you don't have a house you just move into the firestation for a while.
I once played a game exactly as you described by starting off at $0 but she didn't have a house and I didn't let her sleep at the firestation or gym. I placed a park bench on her lot and that was it. She survived by harvesting plants from gardens and community lots to eat and washing up in public restrooms. I wanted to see how long I could keep her poor for. The poor woman never got a job,married or had any children.
Rachel