If magic is not the focus of your first, this should not be a problem.
Dont, however, shoot yourself in the foot by mentioning magic in the first book in any kind of detailed manner. Readers will expect you to be consistent.
If, for example, in the first, your MC is targeted by a curse, but in the next, you explain how curses simply cannot work according to the laws of magic blah blah blah, you have just ruined the reading experience for a loyal reader.
Another option, is to casually mention in the first one, that there are several systems/sources of magic in your world. Then you can create as many as you like later on.
In my own fantasy world, there are three. The science of Wizardry, spiritual Shamanism and dark Sorcery. Not one of my characters in my first novel know anything about magic, beyond the existence of the three. So for my next book, I could write about a Wizard, and for the third, write about a Sorcerer, without worrying about being inconsistent.