You can create a surface with text on it. For this take a look at this short example:
pygame.font.init() # you have to call this at the start,
# if you want to use this module.
my_font = pygame.font.SysFont('Comic Sans MS', 30)
This creates a new object on which you can call the render
method.
text_surface = my_font.render('Some Text', False, (0, 0, 0))
This creates a new surface with text already drawn onto it.
At the end you can just blit the text surface onto your main screen.
screen.blit(text_surface, (0,0))
Bear in mind, that every time the text changes, you have to recreate the surface again, to see the new text.