i need help asap! my main screen is dark and i cant loghtit up again with f6

what i said with the title! f6 is the button to turn the brightness up when i plugged in another screen jt shows this... can someone help me please, its just a box i can type stuff into. .. im so lost.. more to note when i turn the laptop off it turns itself back on i figured this has happened last night when i had it on for a game to download i obviously turned the screen to the lowest brightness so i could sleep and later put the screen down without turning it off my kde connect cant tell that its on either i cant find anything about this on the interne either i clicked ctrl alt f2 and now i cant even type i clicked it again and now it shows the stuff ive already typed again after clicking alt ctrl f3 im in theterminal i think???? after that i typed in ujust bios and left bios and i fixed it!