Ant Sim RTS help, how to create a hexagon tile grid building system

so iv been looking around in UPBGE on how it works, after a while of working on my project i coudent figure out how to make a building system and on how to create a hexagon grid for it and i need a GUI for the building system to select what to build but i don’t know how to add a gui that will be connected whit the building system, coude someone please tell me how?