There are a total of 8 Datacrons on Corellia, but each faction can get only 7 of them, 2 of the Datacrons here count towards Quesh's.
Datacron 1 - Republic and Empire
Codex Entry - Galactic History 81: The Battle of Telos Four
Coordinates: -2661, -3115
The Datacron is located within Labor Valley, the Advanced Product Research Sector. You need to go to the steel beam that's collapsed on the building at -2492, -3081. You need to go up the beam, then on the steel ledge, circle it to its right until you reach its end (the wall). Then, with the wall on your right, you need to move forward, jumping on the next steel ledge..keep walking forward on that ledge, then make a slight right (follow the ledge), keep forward until you reach the refinery-like building (with fire going out a pipe). You'll notice that near the right wall, there's a big pipe that leans down - you can jump on that. Go up the pipe until you reach its top, turn left and jump on the steel building (with beams) which connects to the pipe. After you've jumped, do a right, then