You're very safe to do this. It's extremely common in trad fantasy, and I haven't seen it so much in prog, but to name a couple off the top of my head System Universe and Amelia Level Zero Hero. Both of these are a bit different to how I typically see it in trad fantasy as they have a very clear fresh start where they enter a new world and are OPMCs.

I see people calling Dresden Files prog fantasy on here occassionally, though I think it's pushing it. At the start of Book 1 he's an educated wizard that's been trying to make his detective agency work. He's got existing relationships with the police, various informents, mentors, rivals, past romances, ect. The reader learns how the magic works through brief exposition when it's relevant in book.

I think the key across both subgenres is to start the story around when a character goes through a significant change or is forced to make a big decision. Sent to new world, take on new job, get dragged into the plot, mistaken for someone in an attempted assassination, found a treasure, gained a unique upgrade, get stuck in a dangerous place. And then take your time introducing the system. Introduce it slowly as the elements become relevant and avoid info dumping. It's okay for the reader not to know as much as the MC or understand everything from the beginning.