You must know the display speed, if you intend to display things while your process is running. Displays are generally slower compared to your uC and other similar processing components. Ignoring the time needed to display your data may result in failure. In cases where you implement interrupts in your process, this issue becomes more complicated.
Chinese made TFT Display ! You can not get any support, but low cost compensates that. Here is the help !
Terminals of two touch sensor resistors, one in X other in Y direction are connected to 4 pins of screen. These pins are shared with TFT display signals. Life is easier for Arduino users who just plug and go with “Arduino compliant” products.