We can make certain changes to the itinerary however we are limited in some ways. I would recommend contacting the travel agent with concerns.
Think Sunday best/garden party. It is outside so prioritize whatever makes you comfortable for the day. Expect about 60° weather with a small chance of rain.
We’ll try to pick a secluded spot with minimal walking once we enter the park. You may want to walk to explore though so feel free to wear shoes that allow you to do this comfortably in grass.