Conflicting declaration "int Buttons[0] = 2;

Using the starting Kit I find a programming sentence that does not work. Please help

It should be

buttons[0] = 2;  //set the first element of the buttons array to 2

otherwise you are trying to declare the array for a second time and to make it worse the second one would have zero elements

In future please post your code here and not a picture of it and use code tags when you post it.

Those two lines that mention buttons are not part of the sketch, but a broken example of using arrays.
Remove them.