The hearing should be at a court that is local to you.
You go along and tell the magistrate that you agreed with the lender, and are able to make, payments on 26th of each month. You also state that the agreement related to (only) two months arrears. If there is a representative of the lender who talks to you before the hearing, don't let them persuade you not to go inside to watch and, if required, contribute to the proceedings.
It is possible that the lender would like a court order in place in case you default on the agreement. If you don't attend, they will be likely to get this.
You should also approach your local Citizens Advice Bureau about legal advice. They may or may not be able to help you at court.
It's worth taking any documents that might be relevant with you (bank statements showing payments, copies of cheques, etc.). You can show these to the people at court but don't let them out of your sight.