The mountains represent all the knowledge he has to gain in his future steps. In his hand he holds a flower, perhaps a white rose to represent his purity and innocence.
The Fool in a reading can represent leaping before you look, taking chances, or beginning a journey. Of course there are more meanings determined by the nearby cards and position, but these are some of the basic.
On the downside, it can also warn against foolish ways, not looking before you leap, and being naive.