If I recieved a summons but made payment arrangements witha law firm that is collecting onthe debt, do I need to still go to court?

You will need to file an answer to the complaint with the court.  The complaint is the lawsuit attached to the summons.  If you don't file an answer to the complaint before the deadline set forth in the summons, you will lose by default.  What that law firm isn't telling you when it said, "a judgment will be made", is that the judgment will be a default.  If the default is entered, you will need to file a motion to set aside the default.

Instead of letting that happen, file a timely answer to the complaint with the court with an attached proof of service and serve it by mail on the opposing party's attorney.

At the law library, look for answer to complaint in the index of Pleading and Practice.  This will give you the basic format for writing an answer to the complaint.  The answer denies the allegations in the complaint.  At the end of the answer is the verification which you sign under penalty of perjury .  When you file these documents with the court, attach a proof of service.  You can either use a court form proof of service or you can write your own.  The proof of service verifies the date of mailing to the opposing party.  If you write your own proof of service, it just says that you are over 18 and the attached documents were sent via first class mail unless specified otherwise to _______ (name and address of opposing party's attorney) on ________ (date).  You sign and date the proof of service at the bottom under penalty of perjury.  The date you sign should be the same as the date of mailing and the same as the date you file your documents with the court.