Need help with 2.4 TFT Touch screen

Hi, im new so pls help me if my question is just silly
Im working on my project with 2.4 TFT lcd touch screen and arduino uno with some sensors.
I want the LCD to display the text "Touch to start", and after touching the screen, it will show the value which are receiving from sensors, and the text Touch to start will disappear.
Can i have some suggestions to do this? i mean the algorithm, i dont know what function should i push the tft.print and so on to (void setup, void loop...) Thank you all.