Yes - in order to learn how individual foods affect your blood sugar, you need to test before you eat. Then you test one hour after your first bite & record the number. At two hours after that first bite, you test again, and that reading should be dropping back down into the neighborhood of your pre-meal reading. The one-hour reading will usually be higher, and if it is too high, you'll need to evaluate what you ate & eliminate the carbier components that caused the spike.
After you've been testing & culling foods from your menus for a few weeks, you'll wind up with a tailor-made food plan for your own individual needs. Obviously this requires much more testing that the doctor advised, but once you're well acquainted with what foods you tolerate, and how your body reacts, you can back off testing unless you introduce something new or are eating someone else's cooking - either in a restaurant or somewhere else.