I talk to my clients a lot about this, because they think the guide dog does everything for them. I explain they actually need better than average skills, because with a cane, you feel around for clues/landmarks, but you are much more restricted with a guide dog. Most people use sounds as audible landmarks to tell them when they are approaching things.

They also use something called time/distance estimation (over time, you get a feel for how far you can travel in an amount of time, and you can tell you've walked roughly the right distance) and can give the dog a command to look for something (stairs, door). The dog is usually trained (with a clicker or treats) to recognize those landmarks, so over routes that is travel often, the dog can start to do it automatically. In fact, a coworker of mine sometimes had an issue with that, because most of the time, he would go straight home from work. But some days, he had to go to a grocery store to get something, and the dog would try to get him back on the correct route.

The dogs are also trained to stop at the intersections automatically, and the client listens to traffic/APSs and gives the command for when to cross. The dogs also usually have training to stop a client from walking into traffic (for example, a very quiet electric car is coming), but it is not advisable to force the dog to do that too often. They can have a breakdown.

They learn routes, like that they walk to the end of their street, cross a road, turn left, and the grocery store is through the third doorway, which is easy to find because they play music and you can hear the cash register.

Tbh I don't use a guide dog but these questions are fairly basic and could be answered by spending a couple minutes reading the wikipedia page for guide dogs