In sprint planning, the time-boxed meeting is fixed to 8 hours for one month sprint or shorter for sprints of less than one month. The team should evaluate the capability of work deliver in a single sprint. The product owner ranked and orders the product backlog based on the value of items so the product owner understand the concept.
The scrum goal provides guidance to development team by building the increment where the objective should met within the sprint.
Scrum Sprint Planning Meeting Agenda