Video:
1. in the main menu go to >Insert>Video
2. or create a hyperlink to the video on your computer so it gets uploaded to
the server and is watchable by clicking the link
3. or insert a HTML snippet: >main menu>Insert>HTML snippet

Music:
1. create a hyperlink to the soundfile on your computer so it gets uploaded to
the server and can be heard by clicking the link
2. or insert a HTML snippet: >main menu>Insert>HTML snippet

Search the help for 'video' and 'sound'