just got retropie gifted and I am absolutely clueless, tried to search in google but could not understand anything. so downloaded some ps1 games and put them in psx file on usb. epxected to play them even if files were archived since it worked for NES. then I tried to extract files and only 1 out of 3 games appeared on retropie. so I have only 1 game currently on retropie which gives me game loading screen but cant be started. and I get "no playstation bios file found- add for better compability" found some solutions while googling but those solutions had way more stuff in it which i had to google again to understand. and both my english and tech knowledge sucks. so hope someone can explain what I have to do?

retropie setup version 4.8