How do I link wav. audio files and a wav. audio player to a free wordpress.com site?

I’m not a wordpress expert, but it is their code on their website and I don’t think you can add code to wordpress pages.

There are several ways. From looking at their support documents the first they list is probably the closest to what you want.

Add a link from your site to an outside audio file. Either upload an .mp3, .m4a, .ogg, or .wav file to a third-party server and link to it using our audio shortcode, or if you found an audio file elsewhere online, simply copy its URL.

Back at your site, enter the shortcode, which looks like this: [audio], with the address inside.

For example:

[audio http://en.support.files.wordpress.com/2014/10/istock_audio.wav ]

So just add the line above (including the brackets) to the page or post you want to include the audio in and then change the link to the location of your file on google drive. (make sure you’re using the “sharing” link, and the file is shared with everyone)

if that’s not what you’re looking for, the document linked above gives several other options