the first time I tried to export a file was as an mpeg4 file and a message popped ujp and said I need to download something in order to add audio to the mpeg4 files but it said an error occurred. Now theres no audio in my mpeg4 files. please help
. . . . a message popped ujp and said I need to download something in order to add audio . . .
That would probably be the Dolby Surround Sound codec/activation.
You must be connected to the Internet to do this, start a new project and add one video clip to the timeline and try to export to mp4 - the dialog should pop up again.