Those progression points will have to come from doing other activities at the moment, like fighting, mining, or crafting. Once you've gathered up enough PPs, you'll have to find a magic trainer and let him begin your teaching.

The green will cover the yellow entirely when the trainer has done all he can, and you get to begin practicing. Get a hold of a Red Way glyph, purify it, research it, and start using the found spell on an NPC - the green bar will start to grow and cover the rest of the skill bar, over the red. Once the green is completely full, you will rank up to 1
