What happens when you pull scabs out of our nose?

The same as when you pull scabs off anywhere. It opens up whatever the scab was protecting. Try not to do that, you increase the risk of infection.

If you’re getting a lot of scabs in your nose/general uncomfortable sinuses, that’s because the air around you is very dry. Try a humidifier.

Also, Google can pretty easily answer this sort of question. You’ll get a faster response than waiting around for me.