To see tracked changes, the Fields that were changed would need to have been tracked using Field History Tracking on each respective Object (Prospect, Appointment, Sale, etc). Each Parent Object in the system has a History Report Type. For example, if I wanted to see changes made to the Prospect records, I would run a “Prospect History” Report. If I were looking for changes made to Appointments, I would use an “Appointment History” Report instead. To see changes to all objects you will need to run a History report type for each of the objects in the system where those Users may have made changes. So to see as much data as possible you’d want to run a Prospect History, Appointment History, Sale History, Project History, Product History report, and so on, for all the objects your company uses.
Keep in mind that Child Objects will not have a History Report Type (for example, Sale Item is a child object of the Sale and therefore will not have a History report type available). This is a native Salesforce reporting limitation. Reference this Object Relationship diagram for more on parent/child object relationships.
When creating each Report I will use the Date Field of “Edit Date” and a Range of “All Time” and you will want to add a Filter for the Edited By person(s). In my example, I am filtering to see Appointments that were Edited By either Cathy Call Center or Sammy Sales:
When I run this Report I can see which Field was edited (Field/Event) as well as the old Value in the field, and the new Value.
Remember, the only field changes that will show up in this Report are the Fields which have Field History Tracking enabled on the Object. Turning on History Tracking for the Field does not work retroactively, so any changes made prior to enabling Field History Tracking will not be reportable.