Don't be afraid to approach anyone you see engaging in role-play if you feel that your character would comment on or observe their presence. If they're in a public location and aren't up for perceived 'outsiders' joining a scene then the fault rests upon their shoulders rather than your own. It can be a bit hit-and-miss at times, but don't let that discourage you. You've taken a huge step forward by making yourself open for advice and asking around.
