I wish you had mentioned your qualification.
But since you have written CPT, which is the entry level tests for admission to the CA course, I assume you might be in the 11th or 12th.
Since CPT is the first level, you have nothing much to loose, even if you do not clear the exam.
My advise here would be to first attempt the course, then based on the results, you would know, which area you need to focus on and then opt for a crash course.
Generally a student with good knowledge of Math, and a little logic is able to clear the CPT tests.
Ideally check the website for the previous p