question how do you add mods to the game and where do you find the mods?
Modding requires the fan-created modding framework, which you can download and install here. Once you've done that, you place the mods in your "mods" folder, which will be next to the game's executable.
There's no centralized place to get mods (something we should really fix). You can download a bunch here, and here's two more. There's also this guide for creating your own mods, if that's your thing.