You don't need to go anywhere other than to www.uscis.gov. However, if your I-94 card expired, then you must leave the U.S. Such efforts to renew may lead to deportation proceedings, if the extension is denied and you are an overstay. This more than filing a form. Sometimes, it is warning someone about the consequences of a decision.
Filing for a late renewal requires proof of exceptional circumstances for not filing an extension before the I-94 expired. This is very difficult to prove without proof. Attorneys are hired to help document and present evidence that is likely to help. However, in some situations, an attorney may be unable to recommend filing an application.
I regret that you cannot afford or don't want to afford an attorney. If the former is the situation, then you should think about whether you can afford to make long visits to the U.S. in the future.
If your card expired more than 180 days ago, then you can be banned from lawfully returning for three years upon your departure. If your card expired more than a year ago, then you can be barred from lawfully returning for ten years, perhaps longer upon departure, if you can no longer successfully apply for a visa. The waiver of this ban is complicated. Too often, those who can't or don't want to hire an attorney who mess up the process find it more expensive or arguably useless to hire an attorney after a final decision.
In the end, if a person does not respect and value the privilege of visiting the U.S., then that opportunity can be indefinitely lost. Perhaps, there are other immigration options, but you may need financial help from your family at this point just to appreciate your options with experienced immigration counsel. Some attorneys don't place a value on their appointments, but it is unclear how much dependable legal advice you can get from a free consultation of that sort. You will have to make a tough decision and most immigration attorneys charge reasonable fees for an appointment.
The above is general information, not legal advice, and does not create an attorney client relationship.