When a 16 year old goes to a doctor for check up how many shots do they get?

They should get as many as hey need. Depending on where you live and shots you got as child.

If the 16 year old has kept up with check-ups & recommended vaccines (by the Academy of Pediatrics and CDC) they may not need any vaccines. If they haven’t had any vaccines since age 5, they might need a tetanus booster (TdaP), a meningitis vaccine, and/or an HPV vaccine. See link: https://www.cdc.gov/vaccines/schedules/hcp/imz/child-adolescent.html#birth-15. Please follow up with their doctor.