Your hand pulls open the door knob and you enter the next 20 minutes, at least, of your life. You are not sure about the sign-in process but you proceed to the check-in desk and follow the instructions the front desk person gives.
Then you find a seat and pull out your phone to help pass the time. You might grab a coffee, if it's offered, but you settle in as if you are at home. Ready to wait.
This is a typical scene at your doctor or dentist office.