Not a fan of the new look. If you’re in the same boat, plug:
about:config
into your URL bar, and search for:
browser.nova.enabled
Toggle it to false using the button to the right.
There are functional changes that Nova also introduced: this won’t effect those - only the aesthetic.
Go with LibreWolf. Brave is a sketchy browser run by known bigot Brendan Eich, who supports hateful anti-LGBTQ causes. LibreWolf doesn’t have any of the nonsense that normal FireFox keeps pushing on its users, it just works as a browser should with privacy-focused options enabled by default along with uBO.