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.