How to populate Entity from stored Proc Entity

I created  Entity  from database   Table Category
Auto generated code  is:
  public partial class StoreDBEntities : DbContext
    {
        public StoreDBEntities()
            : base("name=StoreDBEntities")
        {
        }
   
        protected override void OnModelCreating(DbModelBuilder modelBuilder)
        {
            throw new UnintentionalCodeFirstException();
        }
   
        public DbSet<Category> Categories { get; set; }
    }
 Now when I write   the following code all records are loaded into the  table which I do not want to happen

 StoreDBEntities ss = new StoreDBEntities();
               var cc = ss.Categories;
              List<Category> lc =  cc.ToList();

 
1)How to  populate entity from stored proc ?
2 How  to save entity   using stored proc?