First, pause the game. You may notice that you have 3 vandals in your park, with multiple items around the park vandalized. Also, there is litter everywhere, making many guests angry, causing a greater chance of vandalism. Another significant problem is the lack of Bathrooms for such a large number of people! Two of them happen to be next to each other, which is seemingly pointless (towards the middle of the park). These should be the first problems you address. A good way to fix these problems is by hiring many more security guards and handymen. Keep two handymen open on the screen and use pincers to place them over the litter. This will save lots of time.