How hard is it to learn how to play guitar?

Okay lately I have been more and more into acoustic music and I really like the way the guitar sounds. I bought a learning guitar, not like one of those expensive ones. I know that learning guitar is not easy or fast but can anyone help me in telling me how long it would take to learn how to play. I'm just talking about at-home playing, nothing fancy. Oh and I also think of learning from a professional.

Thanks