Help! RA8875 Touchscreen Buttons

I am totally confused with how to give functions to the buttons on my RA8875 800x480 touchscreen. Please help me to give my boring circle some life!

The touchscreen :7" BuyDisplay 12C with FT5206 touch controller
I am using an Arduino Mega 2560

My code is attached...

Thank you

AdaptedSketch_Aug07.ino (2.46 KB)