Where can I find/upload libraries that are needed for the Uno Wifi Rev 2 board?
You haven't provided enough information to allow us to provide a good answer to your question.
I'll provide you with the instructions for installing the boards platform that adds support to the IDE for the Uno WiFi Rev2 as well as the basic libraries:
- (In the Arduino IDE) Tools > Board > Boards Manager
- Wait for the update to finish.
- From the list of available Boards platforms, click on "Arduino megaAVR Boards"
- Click the "Install" button.
- Wait for the installation to finish.
- If you are prompted for confirmation to allow installing the drivers, accept.
- Click the "Close" button.
You can now select the Tools > Board > Arduino megaAVR Boards > Arduino Uno WiFi Rev2 board, compile and upload to your Uno WiFi Rev2.
If you need more assistance after following those instructions, please provide a detailed description of what you're trying to accomplish.