I just went through the same issue and you need to add it to the "Multi-line" view. For instance we wanted to include a lookup to a partner account when adding the product and we then added "Partner" lookup field to the "Multi-Line" view (it's next to the mini console layout.)
Hope this helps.
First of all, considering this is a task which is a part of a course you are taking, it may be worth reaching out to your instructor and asking them for a guideline. It is possible that your instructor may want you to do this once for a single product (not for the whole catalog), so that you can understand that changes you need to do in the Business Manager.