Get yourself a thick skin and treat people as you wish to be treated.
When the likes of Carter Bresson started out in the 40's, we lived in a more innocent world, the general public were facinated by photography and having their picture taken.
Unfortunatly those innocent times have gone and paranoia prevails, both from the general public and ignorent public officials , I ajm sure you will have some wonderfull stories to tell about your street photograpy adventures
My advice would be to start off with a tele lens, say 200mm , and work at a distance untill you get more confidence.
Oh yes and 'know your rights'