Hi there. Agree with Barb. Just wanted to add that we need walking to be fast and to the point of being able to talk but breathing hard. You should have at least 30 minutes a day for 5 days a week for a general exercise requirement. So, that is more than a simple stroll but walking at a fast clip.
Are you walking for exercise? You can walk around your block as many times a day, as you feel comfortable doing. Sometimes, it's more fun to walk if you have a friend to keep you company, but you can always take your MP3 player (or other musical device) and listen to tunes, etc.