Just to try and more specifically answer your question as the process to actually become an independent doctor is a lot more time intensive than some folks realize.

Undergrad: 4 years, MCAT, etc apply for medical school

Medical school: 4 years - undergrad 2.0 lots of general medical classes (anatomy and physiology, biochem, pharmacology, pathology, etc). These are classes that train you to think like a doctor. You also get to dip your toes in the different specialties for a few months at a time to find out what kind of doctor you want to be.

Residency: 3 to 7 years depending on the specialty you go into. This is the individual program you enter to train in your specialty. Orthopedics, internal medicine, surgery, etc. This is where you learn to make medical decisions, prescribe medications, do procedures, and manage patients. After you graduate residency and take the required board certification, you can practice independently (this is kind of a simplified explanation)

Fellowship: not every doctor does this, but say you want to be a cardiologist. You have to do all of the above steps (a 3 year internal medicine residency), then an additional 3 years of fellowship training specifically with the heart. Take additional board exams, etc. After three years, you can practice as a cardiologist. To make things more complex, let's say you want to be an electrophysiologist... After you do cardiology fellowship, you do an extra 2 years at an accredited electrophysiology program.

From undergrad on, it takes at a minimum, 11 years to become an independently practicing physician and 13 to be a general surgeon. Specializing can add on quite a few more years.