They are different but I know the most about printing.

If you had to learn just one program it’d be Blender. Maya if you want to go professional. The blender tutorials are an excellent starting point for character modeling.

For 3D printing, you might want to try a solid modeling program. I’d recommend onshape. It’s a professional tool used by engineers that’s totally free and browser based so you don’t need a serious rig at all.

You can 3D print from a Nurbs modeling program like blender but you’ll spend a lot of time closing holes and fixing things.