It appears from your post that (1) the plaintiff amended the complaint (i.e., what you think was "just an update"); (2) you did not know that you had a deadline to file responsive pleadings to that amended complaint; and (3) having missed your deadline, the plaintiff filed a motion for default judgment.
Your mention [in the comments] that the plaintiff already lost this case in small claims court suggests that the current complaint is his attempt to re-litigate matters (that is, a matter that is res judicata).
If this is so, you should file a response to that motion and your responsive pleadings. There you need to point out --and preferably attach evidence-- that the matter is indeed res judicata and that therefore the court should dismiss the case. This is not necessarily the only defense available to you in the pleadings you file but, without knowing the specifics of your matter, it is impossible to identify what else would be appropriate for you to argue.
You could just show up at the hearing for default judgment, although that is strongly discouraged. It is better that you file your response to the motion & pleadings ASAP. First, because the dynamics of the court hearing might prevent you from adequately presenting your arguments verbally (let alone having them properly assessed by the judge). And second, to ensure that the record of the case clearly reflects your arguments & evidence in the event that this goes to the appellate court.
At this point it seems obvious that you have little-to-no time to become acquainted with TN court rules, aka procedural law or rules of procedure. Same with legal theories, contract law, statutory law, and rules of evidence. But even if you are unable to search for records of other proceedings litigated in your court, you should at all times strive to present and prove your arguments in writing and verbally as clearly as possible so that a judge (assuming that he is not so sloppy or negligent) grasps the merits of your legal position.