I am a Raspberry newbie! Got my first raspberry PI 4 4 GB. And after I installed the OS. And after I connected my raspberry to my keyboard, mouse and monitor, i wanted to activate my 3.5 LCD RPI screen.
So i do exactly as the instruction told me to do. But after i finish the commands my monitor turns black and my LCD is still only white. i tried to do it 4 times and i restarted it several times. But it still doesnt work. Help me! I pull my hair out soon!

Best Regards!