How to find the sql jobs that have not run for more than two months?
There is no way to assure you can get data for that historical range because-

This depends upon the settings of SQL agent where you decided to keep history based on certain conditions , unless left default which again may or may not go that time back.

If you are lucky enough and msdb has the information still stored for jobs 60 days old, you can simply query from sysjobs to get required data and filter based on your need