Control+Shift+H or you can find the link to it in the history menu in the main Firefox menu. Or at the bottom of the history menu from the history button if you add it to your toolbar. Or in the Library section if you use that menu/button.
The sidebar is a cut down overview.
Same for bookmarks, the full bookmark screen has more depth and features than the sidebar.
I’ve had lots of problems with Nvidia over the years; you’re lucky not to. Latest has been with Wayland which are ongoing. That being said Nvidia drivers are much better generally than they used to be, and I’ve not had the myriad of small issues I used to get.
This is less to do with them being closed source drivers so much as their drivers being poorly maintained in the past. They seem much better maintained but even now the software support lags behind windows - you have to use 3rd party open source software to make use of the streaming features for example.