What do I need to buy to connect USB device to my iPad 8 gen?

Your iPad8 has a Lightning port. To connect USB storage to your iPad, you will require an Apple Lightning to USB 3 Camera Adapter:

https://store.apple.com/xc/product/MK0W2ZM/A

You will need to connect (a) your USB storage device to the USB Type-A connection of the Adapter - and (b) connect your Power Adapter to the Lightning pass-through power port of the Adapter.

Additional information can be found within the iPad User Guide:

Connect external storage devices to iPad - Apple Support

To view videos from a USB device on your iPad Mini (iOS 12), you'll need a Lightning to USB adapter. Specifically, you should look for the "Apple Lightning to USB Camera Adapter." This adapter allows you to connect USB devices, such as flash drives or cameras, to your iPad's Lightning port.

Once you have the adapter, you can plug the USB device containing your videos into the adapter, then connect the adapter to your iPad's Lightning port. Your iPad should recognize the USB device, and you can use the Files app or a compatible media player app to view the videos stored on the USB drive.

Please note that the compatibility of USB devices may vary depending on the iOS version and the specific device you're using, so it's always a good idea to check compatibility before making a purchase.

Heretostay59 wrote:

To view videos from a USB device on your iPad Mini (iOS 12), you'll need a Lightning to USB adapter. Specifically, you should look for the "Apple Lightning to USB Camera Adapter." This adapter allows you to connect USB devices, such as flash drives or cameras, to your iPad's Lightning port.

You mean like the one LotusPilot linked to in the preceding post?