Hi Sara. hi Rui,
i do not own a CYD but an Elecrow 2.8″ board. And I bought your new book Learn LVGL. So I tried to run the first two Sketches on my board (Ardiuno 2.3.2). I changed the User_Setup.h file with these items:

#define ILI9341_DRIVER
#define TFT_WIDTH  320
#define TFT_HEIGHT 240 

#define TFT_BACKLIGHT_ON HIGH
#define TFT_BL   27 
#define TFT_MISO 12
#define TFT_MOSI 13
#define TFT_SCLK 14
#define TFT_CS   15
#define TFT_DC    2 
#define TFT_RST  -1
#define TOUCH_CS 33

#define SPI_FREQUENCY        27000000
#define SPI_TOUCH_FREQUENCY   2500000
#define SPI_READ_FREQUENCY   16000000

#define LOAD_GLCD   // Font 1. Original Adafruit 8 pixel font needs ~1820 bytes in FLASH
#define LOAD_FONT2  // Font 2. Small 16 pixel high font, needs ~3534 bytes in FLASH, 96 characters
#define LOAD_FONT4  // Font 4. Medium 26 pixel high font, needs ~5848 bytes in FLASH, 96 characters
#define LOAD_FONT6  // Font 6. Large 48 pixel font, needs ~2666 bytes in FLASH, only characters 1234567890:-.apm
#define LOAD_FONT7  // Font 7. 7 segment 48 pixel font, needs ~2438 bytes in FLASH, only characters 1234567890:-.
#define LOAD_FONT8  // Font 8. Large 75 pixel font needs ~3256 bytes in FLASH, only characters 1234567890:-.
#define LOAD_GFXFF  // FreeFonts. Include access to the 48 Adafruit_GFX free fonts FF1 to FF48 and custom fonts
#define SMOOTH_FONT

Then the first sketch “Displaying Text …” worked without a problem.
But the second sketch “Testing the Touchscreen” refused to work.
But I managed to get it running: I had to alter these lines in the sketch:

// Touchscreen pins
…
#define XPT2046_MOSI 13 // T_DIN
#define XPT2046_MISO 12 // T_OUT
#define XPT2046_CLK 14 // T_CLK
…

SPIClass touchscreenSPI = SPIClass(HSPI);

The important thing was to change VSPI to HSPI and everything worked.

Perhaps is another person out there looking how to work with the Elecrow 2.8″ board and your new book.

Greetings from  Germany

Rudolf