Did you know that husbands and wives each need their own lds.org (FamilySearch) login and password? Teenagers need their own, too! Family Tree relationship connections are tied to individual church membership records. When you log in to the FamilySearch Family Tree using your LDS.org account, you should see the names of your parents, grandparents, spouse, and children. Dates, places, events, sources, and photos are displayed for deceased individuals recorded in the Family Tree. For privacy reasons, you will not see details for living relatives (except birth dates for your children under 18), and will not see a married child's spouse or children, or your spouse's living parents or grandparents.
If you don't see your parents' names when you log in to your own account, see the ward clerk for a copy of your church membership record to make sure the information is recorded correctly there. If you don't see your grandparents and they are also members of the LDS church and still living, have your parents check their own church membership records.
For help untangling your Tree, stop by the Williamsburg (VA) Family History Center!