You are allowed to represent yourself before the patent office. However, it is complicated and you probably won’t get anywhere. If you really don’t have money, the USPTO has a pro bono program (Google USPTO and pro bono). You have to meet various requirements (i.e. income has to be below a certain limit, you have to have some knowledge of the patent system which you could learn, and you actually have to have an invention).
If you don’t qualify for pro bono assistance, you may have some luck with the USPTO pro se assistance program (Google USPTO and pro se).
If that doesn’t work, read up on patent law from the internet. I would not represent myself without being informed.
If you have some money to spend, try to get a patent agent. Since they do not have a law degree, they usually are cheaper.
Hatzlocha.