Pygame font error

You never initialized pygame and pygame.font after importing:

# imports

pygame.init() # now use display and fonts

In order to use some pygame modules, either pygame or that specific module has to be initialised before you start using them - this is what the error message is telling you.

To initialize pygame:

import pygame
...
pygame.init()

To initialize a specific library (eg font):

import pygame
...
pygame.font.init()

In most cases, you will want to initialise all of pygame, so use the first version. In general, I would place this at the top of my code, just after importing pygame