Absolute noob needs advice

So, since very recently Nintendo decided to be a fuck and kill all emulator projects for the Switch, I finally decided to grab them and learn how to use them. I'm very much not new to emulation in general and where to find games, so I'm mostly good with that. Only thing is that I couldn't get the new Zelda game to run without stutters, but I guess that's the shaders compiling in real time. Unicorn Overlord plays absolutely flawlessly.

Anyway, I would like to go after more games, but all of the different file formats confuse me. Specifically, the NSZ format. None of my emulators are able of loading that, my other games are in NSP format and load just fine.

Okay, also. I own a 2019 model Switch Lite and would like to know how would I go about unlocking it. I guess I would need to install a modchip on it?