I think you can have parents, 1 friend per competitor (ask your teacher), your English teacher or staff from your school and the adjudication judge watching.
What zones are you competing in?
@darlking: Impromptu is any topic they give you and you have to speak about it, not much you can prepare on paper before hand...
If you just select Custom without changing the setting (e.g. selecting specific people/lists to make visible or hide from) than it's on Friends of Friends...
I believe that there are some people who think Custom (default) is actually more private that Friends Only but don't realise that it is actually Friends of Friends. Facebook is "smart"...
What's your general Facebook privacy setting set to?
Public (Everyone)
Friends of Friends
Friends Only
Custom (Friends of Friends) ~ Custom = Friends of Friends by default unless changed
Custom
Only Me