well it's pretty hard to know if someone's gay or not just by looking at them, and asking them could either put you in a daqngerous position (if they're actually homophobes and they figure you're gay) or put them in an an awkward position (they might not be ready to admit they are gay yet). So if you want to meet gay and bi people your own age, the safest and most practical thing to do would be to go to one of the bitbents, which I believe are held on Thursdays at Woden Youth Center and mondays at Belconnen. I don't know the times, but you can find them on this site. I went to the Woden Bitbent once, and I'm pretty sure it's exactly what you're looking for - it's jsut a place where you can meet and talk to other people like yourself.