Hannah,
A few thoughts on Mt. Blanc and the Aiguille du Midi......
The Aiguille is one of the peaks of Mt. Blanc. The ride to the top from Chamonix requires two cable car rides, the first to the mid-point station and then another to the top. You can also take the Mt. Blanc Panoramic which travels above the glacier to Pointe Helbronner in Italy. Another cable car at Pt. Helbronner goes down to Courmayeur, Italy.
One important point to mention is that the visitor centre on top of the Aiguillle is at about 12,600 feet, so the altitude can be an issue for some people, especially if staying there for several hours. It would be a good idea to familiarize yourself with the symptoms of altitude sickness, as it can be very serious. If you have any health issues, you may wish to ask your Doctor about this.