Since you're getting a caps lock then the computer is most likely still on and if you press the shift key and volume up or down you will get a volume sound meaning its still on. You probably have a damaged display or possibly a damaged backlight circuit on the motherboard. Your usb-c ports are probably going to need replacing too. I would stop using it and take it somewhere to disconnect the battery ASAP since this can get worse and possibly fry the motherboard if left in that condition. A shop that can repair motherboards will most likely be able to fix the liquid damage on the motherboard and a bad backlight circuit. If the screen is damaged then unfortunately there's nothing you can do other than replace the display.