The world in logo is a coordinate system of patches. Each place in the world is a patch. You can control the size of the world.
ask patches [stuff]
stuff settings for patches:
set pcolor <color>
if <condition> [<..>]
if not any? patches with [<condition>] [stop]
ask turtles [ <stuff> ]
set <variable> <value>
set label <value>
To provide state to an agent:
turtles-own [variable]
Add a slider with the UI to let the user set a variable which can then be used by name in the code.
Add a plot with the UI to watch a variable: sum [food-eaten] of turtles