The two girls began trying to cast a healing spell while Vance held out his hand toward the ground and tried to remember the magic circle for a basic earth wall spell. The reason he wanted the girls to learn healing was to make it so that the team's survivability would be much higher.
He himself wanted to take this time while they were training to learn earth magic. It was a vital skill since there were higher level skills like rock armor and stone skin that came from the earth magic line that he would need for defense later on. These were all essential skills for him. Earth wall was the first of the earth spells, so he wanted to start from there and work his way up since earth wall's magic circle is what the other spells were based off of.