Android phones and tablets can connect to and read USB Flash drives and SD cards
Using an inexpensive connection adapter, you can connect many USB storage devices to your Android phone and/or tablet. Many of the newer Android devices have an USB Type-C connector which will universally connect several types of storage devices.
Check out these inexpensive adapters you can purchase from Amazon:
Also available are USB Type-C flash drives that will connect directly to your Type-C port on your Android phone or tablet without using the adapter:
Please be aware that these may not be compatible with all phones or tablets with a Type-C port. Refer to your devices documentation for compatibility information.
Connect the USB flash drive or other device into the Type-A USB port first, then connect the Type-C connection last.
Open your file manager and the Android device will see the external drive as an SD Card. The Internal Storage is the storage that is on your phone or tablet. You can now easily copy files from your internal storage to the SD Card, or vice-versa.
You may also directly add an internal SD memory card, click here for more information: How to use an SD memory card on Android phone or tablet?
Which SD memory card is best to use? Which SD card to use on an Android phone or tablet?