In order to start preparing, take up the subjects most relevant to the exam. Read more about civil services.Take up a graduation course that involves history and political science. If you start your IAS preparation early, you can grab a chance to clear the civil exam and start your civil services career early. This will take you a long way in your career.
You should take BA with Polity and Sociology/History. Make your basics strong. And in 3rd year you can join coaching. Preferably online. 6395716036 whatsapp for any help.