I am thinking of going into pediatrics to treat infants, children, and adolescents.
That's awesome!  General pediatrics or specialty?
Pediatricians could do either, but I think I would like to be a primary care physician rather than specialize in something like neonatology.
What kind of schooling would that require?
MBBS, or DO). To become primary care physicians, medical school graduates then undertake postgraduate training in primary care programs, such as family medicine (also called family practice or general practice in some countries), pediatrics or internal medicine. Some HMOs consider gynecologists as PCPs for the care of women and have allowed certain subspecialists to assume PCP responsibilities for selected patient types, such as allergists caring for people with asthma and nephrologists acting as PCPs for patients on kidney dialysis.
Emergency physicians are sometimes counted as primary care physicians
American Osteopathic Board of Pediatrics
The American Osteopathic Board of Pediatrics (AOBP) is an organization that provides board certification to qualified Doctors of Osteopathic Medicine (D.O.) who specialize in the diagnosis and treatment of medical diseases in infants, children, and adolescents (pediatricians). The board is one 18 medical specialty certifying boards of the American Osteopathic Association Bureau of Osteopathic Specialists approved by the American Osteopathic Association (AOA), and was established in 1940. As of December 2011, 477 osteopathic pediatricians held active certification with the AOBP