Here's my 9 things to do at Diagon Alley since I am now registered at Pottermore:
1. Go To Gringgots and exchange my currency for galleons, sickles and knuts.
2. Get measured for robes at Madame Malkin's Robes for All Occasions
3. Check out books at Flourish and Blotts
4. Buy an owl at the Eylops Owl Emporium
5. Check out the Apothecary
6. Visit Weasley's wizard wheezes
7. Ogle at broomstick display (while planning to apply for Quidditch)
8. Most Importantly: Buy a wand at Ollivander's