CMOS is a battery function, not computer battery, but a smaller flat one. Take the battery of, wait for for a minute, some recommend up to 10 minutes, plug it in, and starting the computer you should get a notification "Start with default settings", or something.
BIOS password is another thing. What message do you get when you start the computer? And not to forget, why do you need to get to CMOS? 99% of users never touch it.