This was not valid service of process.  The process server was informed that you did not live there.  Since you were unaware of the documents being served at the wrong address, you could not have filed an answer to the complaint (complaint is the lawsuit attached to the summons) within the thirty days set forth in the summons.  The opposing party, erroneously claiming that you were validly served will file a default judgment with the court since your answer to the complaint was not timely filed with the court and served by mail on the other party.  A default judgment means that you have lost.  You will need to file a motion to set aside the default.  Your argument is that you were not validly served and were unaware of the attempted service and therefore could not have timely filed an answer to the complaint.  If the court grants your motion to set aside the default, the case will then be back on track and litigation will continue.  Since you are out of state, file your motion to set aside the default by mail and serve a copy on the opposing party by mail.  When there is a hearing on your motion, the court may allow you to appear by telephone since you are out of state.  Check with the court clerk to obtain the appropriate forms for requesting a telephone appearance and how far in advance of a hearing the request for a telephone appearance needs to be filed.