Very good if you want to choose CA as your career.CA is a professional course for which you should be 12th pass.
It is divided into 4 stages.After passing your 12th you will have to enroll with ICAI and give CPT exam .
When you qualify CPT ,you will have to give IPCC exam which is second stage.
After qualifying them,you will to do articleship training under a practicing CA.
Final stage is final exam and after qualifying it you become CA.

After your 12th, you are interested in Charterd Accountant, to be eligible for this you should be 12th pass. Candidates who have completed graduation or post graduation in Commerce stream with a minimum of 55% marks in aggregate of all subjects or its equivalent from a state or nationally recognised university are exempted from CA CPT.

You can go through the complete eligibility criteria here.

This year CPT application date is over. You can start prerparing for the exam meanwhile for next year attempt and for the exam make sure you know the whole syllabus before starting your preparation. 

Good Luck.