Hi, great to hear about being interested in doing a documentary
First of all do what you want to do, I've seen excellent documentaries, and the best one was just someone (never seen) interviewing a person. It's called The Last Days. very memorable and simple.
Just follow this and I'll assure you success: link
_________________
One of God's own prototypes. Some kind of high powered mutant never even considered for mass production. Too weird to live, and too rare to die.