I got my first request in Cornelia.
First you need to Talk to the princess in cornelia. After that you will find a Knight in front of the fountain who requests an earth Hammer. Head into the Nether Nebula and proceed past the first Switch. Not far away there's a second switch. If you activate it you"ll find the Hammer in one of two chests.
After completing the chapter head back to Cornelia and speak to the knight again.