Seeing as you're coming from Windows and already have familiarity with Ubuntu, I'd say go with Ubuntu. The difference between Windows and Ubuntu is pretty minimal, and Ubuntu has amazing support because of it's popularity finding an answer to any question is a simple search away. The FPS gains from a leaner distro will be minimal compared to Ubuntu and you still get a fully functioning, well maintained and supported system.

I wouldn't recommend you venture too far from Ubuntu but if you're feeling a bit adventurous, Pop!_OS is based on Ubuntu and is a great option. Any of the Debian based distros would also feel similar to Ubuntu and Windows and will generally offer a user experience that a Linux noob should be able to get into as you gradually get used to using the terminal rather than GUIs.