There are no actual levels. However you could set your own levels if you'd choose. Such as for a specific area of magick. For example:
Lv 1: heating ur body up x amount of degrees
Lv 2: lighting a candle w/o match
Lv 3: Putting out candle by thought alone
Lv 4: creating fireball in hand
Of course this example is just a quick put together, not really thought out or anything. But you can see what I'm going for.