If you forgot what you granted, go to the Add-ons section, which lists all the permissions you granted.
Tips for assessing the safety of an extension gives tips on keeping bad stuff out (always a good idea).
Extensions in Private Browsing might be another option – just keep all the extensions turned off, like:
Starting in Firefox version 67, you will be able to decide which extensions will run while you are in private browsing.
Your choice, of course. Keep in mind that it’s not supported. Note also that my comments apply to the recent versions of Firefox. If you’re hanging onto an old Firefox too, it’s far worse, and has other bugs.