Just wanted to share detailed plans that are recommended by TouringPlans. At the least, it is a good checklist of what there is to do at both WWOHP.
Wizarding World One-Day/Two-Park Plan PART 1
(At step 7, See part 2 of the plan)
Step 14 mentions Knockturn Alley, you definitely want to walk through there. And I do think you guys will enjoy the Ollivanders (wand shop) Experience.
If you don’t have a meal at Leaky Cauldron, I would consider just ordering Butterbeers there and enjoying the inside. And definitely have a meal at Three Broomsticks, very good food.
Wizarding World One-Day/Two-Park Plan PART 2
If you want a detailed map to better understand both WWOHP, you can look at these.