>>3278611For learning, mirrorless is much better, the viewfinder shows exactly what changes adjusting the iso, aperture and shutter speed have as you make them, whereas a dslr is just a fancy window.
Mirrorless is also super cheap to play with as you can adapt any lens from any mount onto it and it has loads of tools there help you make sure you don't fuck up the exposure (zebras and wysiwyg preview) and nail focus regardless of lens or light (eye af, focus magnification and focus peaking).
Advantages of a dslr include longer battery life and a more established lens selection, although both these gaps are much smaller than they were 2 years ago.