The mirror cube is one of the most easiest 3x3 shapemods. It's essentially a normal 3x3 but you have to identify pieces with the depth/length. Depends on what mirror cube you buy, you won't have parity. If you want to solve more shapemods I recommend Fisher and Windmill cube. Once you get used to shapemods you can go to the Axis and Ghost cube. They are the most popular 3x3 shapemods.