How do I solve this cube?

Question

I’m trying to learn the cube but I'm stuck. How can I solve this in the least number of moves?

The answer is a phrase. Since it’s a secret phrase, an abbreviation will do.

Answer 1

Took a bit of time to assemble a cube with that pattern, but it can be solved:

In just five four moves.

The book in the images is "The Simple Solution to Rubik's Cube" by James G. Nourse, which uses its own notation for moves, so we'll use that here.

Calling green side Top and the yellow side Front, the shortest solution is:
R+, T+, F+, R+, L-
(In the more common Singmaster notation, this would be R, U, F, R, L')

But that's five moves I hear you saying.
Well, yes it is, but if we replace the final pair of moves (R+, L-) with an equivalent twist of the Middle slice between them, we end up with a shorter solution of:
R+ T+ F+ M

Which is clearly telling you how to solve your cube by Reading The Fine Manual that is sitting underneath it.

Answer 2

Based on the sides we can see, I believe this is the configuration of the cube

The least amount of solves required is:

R U F R L' (according to https://rubiks-cube-solver.com/ because I'm not good enough to work it out by myself yet)