Guide dog users, as well as other visually impaired persons, are equal with the sighted, and no special treatment or attitude is needed. Sometimes they may need help, as any sighted person does.
When it looks as a guide dog user is lost, or isn't sure when crossing a road is safe, it's polite to offer help. Offering help means asking the person if he needs help. You are in no case allowed to talk to the dog, or interfere in its work in any other way.
A guide dog can not read traffic lights. If the traffic lights don¦t have any sound system, the person listens to the flow of traffic and decides when it's safe to cross the road. It's polite to tell the dog user when it's safe to proceed.
When a guide dog has the harness on, it is working and must not be disturbed. Especially a young dog can be disturbed even if you are just looking at it. In no case you are allowed to feed the dog.