Hi jordan2891,
Welcome to Apple Support Communities. We understand that you're having an issue with playing audio files from your Files app. We'd like to help.
From what you've shared, it sounds like the file is not in a format that can be played on the iPhone. Typically, files here can play but you may need to complete a few steps to get this to work for you.
Do you have access to a computer? You will want to convert these files there. Check out these steps that will allow you to convert the files on a Mac or a PC:
Convert a song to a different file format with the Apple Music app or iTunes for Windows - Apple Support
Let us know if this helps.
Take care!