@Lucie2022 Let's say the two numbers are in A1 and B1, then use something like this:
=IFERROR((B1-A1)/A1,"N/A")
As long as A1 is not equal to zero, it will return a the difference between the two divided by the value in A1. Format as a percentage. Otherwise it will return the text N/A or whatever you want. Just replace "N/A" with what you want to display in such cases.
