Quick questions on classes pygame

[ben.juarez.773]

I have scoured the internet, but to no avail. Perhaps someone can point me in the right direction about the following for Classes in pygame:

1. Item One: I would like to make random enemy movements within each class or subclass.
2. Item Two: I would like to change the color of individual, created enemies from a class that contains the same type of character (player is a circle, and so are the enemies, so why make a separate class?)
3. Item Three:I would like to create a boundaries, so that if the player travels outside of the screen, the game is over.

Still a beginner, so I apologize if you've answered these questions before.

Thanks in advance!