While Dustin Hoffman is not in the movie, the roles you're thinking of are:
* Mandy Moore plays Jamie Sullivan, the female lead.
* Shane West plays Landon Carter, the male lead.
* Peter Coyote plays Jamie's father.
There seems to be a bit of confusion about Snoop Dogg. He is not in "A Walk to Remember" and there is no record of him ever collaborating with Mandy Moore or Dustin Hoffman on any film project.