I am wondering what liquid or product I can throw on the ground, pavement and in the woods to keep the children and teenagers, and adults away from the areas? They try to hurt cats and other animals as well as people that unfortunately walk by them..
I need peace of mind what to do about the situation short of calling the police..
thank you

Terrible situation.
I'd involve the police and I'm with Randall.
Just protecting that one area won't suffice.
IF you want to do magic on those ... folks (there are much unfriendlier words I have in stock for such people, but it should be pg-13 here), then you should consider a serious ban/curse to keep them from doing it elsewhere, too.
But before you get involved into such an enterprise, I'd recommend some divination.