Hi Gauri,
Here in the US most medical students get an undergraduate degree usually taking 4 years to complete. You then go on to 4 years of medical school (there are some programs where you can do both undergrad & medical school in a total of 7 years instead of the normal 8). The first 2 years of medical school are basic sciences and the 3rd & 4th year are clinical rotations. When you graduate you enter a 1 year internship (which is essentially your first year of residency but just called internship) then on to residency. The length of residency depends on the field you decide on and if you want to specialize, subspecialize, etc.
Hope this helped! 🙂