Remove every "AdBlocker" and install a real one, aka uBlock Origin. AdGuard is definitely a good extension but imo uBlock Origin is the way to go and using multiple have been proven to harm blocking capabilities.

I suggest going for addons recommended by Firefox.

For blocking ads and other annoying content, I suggest uBlock Origin. It allows you to customize your experience, and can have the same or better effect than some other extensions. It is also not recommended to use multiple ad blockers, as they may conflict with each other.

For deleting cookies, I recommend not using an addon, but the settings of Firefox. Under "Cookies and Site Data" you can choose to delete cookies on close and manage exceptions for the cookies you want to keep.

For translation, Firefox Translations is fine.

Search by Image, I never used but it is recommended.

I usually avoid "redirect skippers". As they can be as problematic as the initial problem itself. I cannot find FastForward in firefox and Skip Redirect is not recommended by firefox.

edit: spelling

Mullvad for the VPN. And you don't need the ,,AdBlocker for YT" and especially not ,,Ad Block Plus" combinef with ,,AdGuard" use one of those or switch to uBlock, but those I mentioned are safe (Excluding YTADBlocker, don't know that one)