I don't know anything about this specific course, Fania, so can't comment on it but there are other similar short courses in London at the London Film School and Met Film School you might consider as well.
There's a limit what you can do in a month but it could be a valuable experience. It's likely to be fairly traditional in its approach, which is no bad thing; what you're planning, however, is rather more ambitious and not just a standard "documentary".
Are there any other films you know that resonate with you? Jonathan Caouette's Tarnation is worth looking at. You can also learn from Doug Block's work, also his checklist for "personal docs"