It's rather may be very easy question but quite useful for me now.
I saw a code in the basics to make a cube, but how do you make a textured cube with multiple textures on it?

a Mesh is an array of MeshPart's
each MeshPart can have a different material set.

so you can setup the cube in Mesh Editor (split it's faces into multiple MeshPart's and then set a different material for each face)

Sorry for not mentioning it before, my question was on the in built cube generator.

you would have to program it manually using Mesh methods
builtin cube generation method only does what you can see

oh ok.. thanks for the info.