Where can I find my recorded voice?

They appear to be stored in the app folder so not easy to get to. You can share the file to save a copy somewhere else or save to Google drive. Otherwise it seems we are not intended to manually access them. I found it worked to open the File Manager and search for the files.

To check out your voice activity, head to Google's Voice & Audio Activity page. You'll see a long list of your recordings which include the date and time they were made. To listen to them, click the play button. A lot of the recordings you'll find are saying commands to open apps or checking the weather.

On your iOS or iPadOS device: Go to Settings > [your name] > iCloud, tap Show All, then turn on Voice Memos.