How to store a word from serial monitor?

This is not the correct library for that type of LCD screen.

This type of display is notorious for not playing nice with any other SPI devices. The display itself, the SD card reader and the touch sensor chip are all 3.3V devices, so the board also contains logic/signal level shifters to allow it to be used with 5V Arduino. Unfortunately, that part was badly designed and prevents other SPI devices working.