With presidents regularly overturning EOs of previous administrations, it is important to know the disposition of executive orders. The National Archives is charged with this task. The federalregister.gov site does this for recent administrations.
For older EOs going back in time, use the older NARA site at https://www.archives.gov/federal-register/executive-orders/disposition. A handy resource for this is the book version, Codification of Presidential Proclamations and Executive Orders.