Hello @matt423 !
This may be of interest:
And this:
https://funprogramming.org/60-Are-two-circles-touching-or-intersecting.html
Both of these examples are processing java not python. So use as a basic roadmap for concepts to solve your collision question.
As for adding more boxes. Please explain more specifically what you want to happen. Do you want boxes to appear via user interaction? Please clarify.
Finally, it is much easier to read when code is formatted to look like this:
void setup(){
size(400, 400);
}
void draw(){
}
And so, please format using the </> icon in the toolbar. 
