Thanks so much guys for your replays. You gave me good clues and a boost to my confidence.
I still wonder how could i find people who are not students.
I think i am more interested in more unpredictable people. People that you know, are old (er) or have nothing to do with the arts...
I am obviously rather insecure about whether they would ever accept to be filmed but the first question is where/how could i approach them.
I guess again clubs and societies are perhaps the best way.
It is ashame how people we are kinda categorized and the only way we can be found or addressed is by belonging to a little society we have to pay to be part of. Or be sick on body or mind and thus to belong to a different institution.
But its late and i probably don't make much sense.

Anyway, thank you for your help everyone!!!!!x