where do i look?
Where you look is determined largely by what you are looking for. If you are looking for the Schrogham Family Tree, you will not find a tree labeled in this manner at FamilySearch/Family Tree since all guests of Family Tree use the same large single tree. If you are looking for people in FamilyTree with the last name of Scrogham, you can log into most pages of FamilySearch/FamilyTree and click in the left upper corner on Family Tree, then Find. You will then be able to click Find by Name. You can then enter the information you have, especially the name, a place or places, and any dates for life events, and search for that person. You will usually then find people that match your information to some degree or even the exact person for whom you are searching.
You also could benefit by using the Help Center found by clicking the small circled question mark in the right upper corner of all FamilySearch/Family Tree pages, then in the drop down menu, click Help Center. If you then click the icon for Family Tree, you will see numerous articles with information that could be very useful for you.
If you need more information, you can always ask here again with more specific information about for whom or for what you desire to find.