Hi faylanes,
It sounds like you're trying to import files from a USB drive or external hard drive to an iPad. We're happy to offer some guidance.
You'll first want to make sure that you have the USB accessories option enabled in Settings > Face ID & Passcode > USB Accessories.
Using USB accessories with iOS 11.4.1 and later
If the USB device is using a USB-C type connector then you can just connect it directly to the iPad. If the USB device is using the older square style USB connector, then you'll need a USB-C to USB adapter to connect it. Here's an example of one that Apple makes: USB-C to USB Adapter
Once you've got it connected up, you can use the Files app to move the files from that device directly to the iPad. You can find the guide on using Files here: Use the Files app on your iPhone, iPad, or iPod touch
Hope this helps. Cheers!