You'd know if you made a backup copy of the folder.
If the file path looks like this Documents/Electronic Arts/The Sims 4/Mods then you're in a correct place.
If it looks different then it's either a backup copy you've made, or possibly you're working with a cloud copy (iCloud/OneDrive/Google Drive) instead of a local folder on your PC, and not actually making any changes, which is a common mistake.