With your entry ticket you will get the audioguide with several languages. There is a walking route with places of interest, where you can listen to the commentary and move around. I thought it was a great way to learn about the history of the stadium, rather than reading displays. It was nice to be in the fresh air and listen to the stories.
As you progress around the stadium, at one point you will go inside and walk the same path as all athletes, who competed here, would follow.
There is also a small museum with posters from past Olympic Games and original torches. I loved that part as I was able to see torches up close and also learn creative ideas behind instantly recognizable posters. Some of them are a symbolic marriage of the Olympics and a country/city where the games were taking place.