Once you get 10 student level, you can then unlock apprentice mage.
(Provided that you've also managed to get Mana Control up to level 400.)
Once Apprentice Mage is level 10, you can finally extend your life.
The best strat is to level up both Concentration and Meditation as much as they can go. I managed to get each up to 440 before I started extending my lifespan. It's best to switch back and forth levelling each one up.
This game hinges on living until you're 200 years old so you then take an evil route. I'm trying to refuse evil and it might be impossible to play long-term. The XP requirements for levelling up exceed any wage you can reasonably earn to pump your bonus from the shop.