All your files that contain video, including the linked mp4 above, look like this at the head - then pure black...

If the project plays on the timeline with video and all the intended audio tracks, then it should save (not EXPORT)... Click Menu (top-left) FILE, then BACK UP PROJECT FILES TO FOLDER. Note where it's going to be saved and click SELECT FOLDER. The new numbered folder you just saved needs to be uploaded to Google.
If video is simply a single file (slender white "spirit" figures in a jerky animation), upload it alone and link here. What is the name of that file? The 'bells' may have been a sync mark, and edited out. They are not heard on the timeline.
Don't see how you got the m4a files into VP, as they wouldn't load here. After conversion to mp3, all did load and the timeline appears to reflect what you intended. Several audio clips have an AMPLIFY 100%, or multiples of that effect applied. But an amplify 100% does nothing. The slider must be moved to either lower or raise the volume. Delete the effect or move the slider. Use no more than a single AMPLIFY effect for each clip.