I called the HR Manager for a large healthcare company, explained my situation and asked if they could place me in shadowing positions. Be courteous and thankful. They will have questions for you about why you want to do it and will deny if you don't have a very good reason (like trying to attend medical school).
The lady was awesome and had me shadow several doctors over several specialties for about 3 weeks straight.
I also just randomly called clinics and was lucky enough to reach an amazing GP who was flattered I would even ask to shadow her.
My experience has been talking to receptionists and low level employees is not helpful. They typically don't understand the process and will defer you or never get back to you.
Expect to provide all your vaccine records, submit to finger printing/background checks and fill a bunch of paperwork and sign nondisclosure's. This may cost you some money for the checks.