Playing a single file
Go to your drive and long press on a media file to access file options. Tap "Play" to play a file.
Playing all files in a folder
Step 1: Tap the three dotted line at the top right corner of the bar.
Step 2: Tap "Play All"
Playing Multiple files at once
Step 1: Tap the three dotted line and choose "select"
Step 2: Select the files you want to play. You can also select multiple files. Tap "Play" to play files from your drive.