When should we enable the `locate` command on a Mac?
Once created, according to the man page for locate, the database is updated, automatically, every day or week. I suppose it's one of the daily/weekly scripts that run automatically and that can be forced to run by the app OnyX.  As to the difference between find and locate; since locate is said to be a "find filenames quickly" command, I suppose find doesn't use the database. So I'd create the database at your earliest convenience and then it'll get updated automatically in the background.