I'm cooking a mozzarella stuffed meatloaf, can i replace the mozzarella with queso fresco?

How did it come out? I think better to leave out the cheese and just crumble some on top of the meatloaf slices after it is cooked.

Yes/and if you want to or only have queso fresco on hand.
But there will be different taste & texture because they come from different methods of production, melting texture & taste.

You can, however queso fresco doesn't melt like mozz does. It will be in the same form (cubes, crumbles) after it's been baked. If you are looking for a melty, gooey cheese experience, go with something else.