Like the earlier games, you can only use Town Portal properly when you are fully promoted. You need to be an expert in elemental magic and to know light magic for the spell to work, and with this level of skill, you can get to the nearest altar. Mastery in elemental magic allows you to pick the destination altar, and grandmastery allows you to portal out in the presence of enemies. There is however one thing you must do first. The altars have been allowed to deteriorate, and you have to repair them before you can use them. Basically you have to find them and click on them before you can use them. Most of them are easy to find, but you might have to hunt around a bit for the ones in Guberland and Frosgard. 
Regarding spells, I'm not quite sure what your problem is. Try pressing B on the keyboard - that should give you normal access to your spellbooks. A character with normal skill in spirit magic and light magic can learn the heal spell, and you can buy the scrolls from which he can learn it from any of the town libraries.
HTH! 
