Best restaurant in San Pedro is Robbie Mar - amazing fish and beautiful inside. It is next to the fish market. Turn right at the main roundabout coming into San Pedro from Juan Dolio and it is about 1/2 mile down there on the right.
For a beach on the way back stop at the Pescador restaurant in Guayacanes as there are sunbeds and you can have something to drink there too.
Matilda