If you have yet to finish the Terran Conflict plot, you will need to complete it here.
If your Terran rank is too low, first thing is to increase it.
You can head into Terran Space to do mission, or kill enemies. Or use Diplomacy to help raise your rank. You will need to go into Terran Space to discover some station to send your diplomats too
Once you have gain enough reputation, you can then start Terran Conflict bridge mission (If you haven’t already, and are not a Terran start).
The Terran Escort mission is found in the Argon sector, Omicron Lyrae, found to the East of the Universe.
If you have already started the Terran Conflict Plot, you simply need to continue it until its complete.