Is there a lot of walking to see the Tiananmen Square?

The square is large, and it takes about 25 minutes for a brief visit. But it is very flat, and you don't need to go stairs to reach the Forbidden City, just a short bridge not steep at all.

Inside the Forbidden City, some palaces were built higher above ground and you need to climb some stairs to enter them. And the royal palace is also very large and it may be challenging for you to walk all the way there.