They are class skills, so if you pick a class that has them, they start at 1, otherwise they are at 0.
I am aware that a lot of the spells don't work if you have 0 skill, and theres no way to get that if you are a warrior for example. That's one of the things I'm working on tweaking right now so that magic is a bit more accessible but also still feels much more powerful if you play a mage.
For now, you can just use a value of 1 in the calculations if you have 0 in that skill.