Hi Torrey,
For the first part, you probably pressed the Y key, which separated the two side Faces from the rest of the Cube.
For the top Face….think about what you’re trying to do; a single Face is 2 dimensional. The top Face has a thickness (dimension in the Z-Axis) of 0. Scaling in Z multiplies that thickness of 0 with a scalar value, but multiplying 0 with any number results in 0.
