If you been arrested and need a lawyer and cannot afford to hire a lawyer because you have no money or just cannot afford a lawyer then you have the right to have a lawyer appointed to you in the court.
You can also represent yourself in court but having a lawyer who is well versed in the law will be the best option.
If you need to hire a lawyer and cannot afford one you may need to get a loan to hire the lawyer and some lawyers will even fight for you in court and you don't have to pay them until you win the case.
Then the lawyer is paid out of the fees from your winnings in the lawsuit but that is if you're suing someone in court and not for a criminal case.
Try checking out a law school as sometimes they'll be able to get you a lawyer without having to pay upfront fees.
Some lawyers may also even take a percentage up front to begin working on the case for you and then setup a payment plan for you to make payments for the lawyers fees.