I thank you for the good information.
Go early for the security check. Audience begins at 10:30 AM on Wednesdays. But usually, they've got pre-program stuff, like a chorus singing the Psalm chant for the day, a band playing. Then at 10:15, the various bishops appointed for each language group will get up and read the psalm.
One big tip....get a center aisle seat because the Pope will come out of the right gate (when facing the Basilica) and go down the aisles. People WILL stand on their chairs. If you get an aisle seat, you have a very high probability of shaking his hand.
Observe the dress code. The guards will send you away...no shorts, no tank tops, no short skirts.
Bring water and a hat. Make sure your camera batteries are working. Bring an umbrella just in case. The weather is changeable.
When the different groups are recognized, people try to outdo each other's enthusiasm.
At the end, when he'll give the blessing, you can get out your rosary (or pile of rosaries from all the friends and relatives who sent theirs to you to have blessed) to be blessed.
Prepare to have your heart swell with love when you see him in person. No matter how stoic you are, it will hit you like a ton of bricks.