CPT Preparation

For fundamentals of Accounting- ICAIs CPT Fundamentals of Accounting Study material
ICAI CPT Mock Test Papers
ICAI CPT Model Test Papers of Fundamentals of Accounting
For mercantile law- ICAIs CPT Mercantile Law Study material
ICAI CPT Law Mock Test Papers
ICAI CPT Model Test Papers of Mercantile Law
S Hand Mercantile Laws for CA CPT by P S
For General Economics- CPT General Economics Study material by ICAI CPT Economics Mock Test Papers
ICAI CPT Model Test Papers of General Economics
For Quantitative Aptitude
CPT Quantitative Aptitude Study material by ICAI CPT Quantitative Aptitude Mock Test Papers
ICAI CPT Model Test Papers of Quantitative Aptitude.

Hi Vaishali,
You are going from science to commerce.
Initially, it might take you some time to understand the basics of commerce, but you'll be fine.
Regular college or not, should completely be your decision.
Anyways once you clear your cpt and proceed ahead with CA course, you have to have your training which might clash from your college.
Plus your CA exams might also clash from your college exams, depending on the college where you get admitted.
However, if the doubt in your mind about joining a regular college or not has creeped up due to your decision of going with CA then it's baseless.
You can easily cope up with both graduation and CA together.
Further to inform you, it is suggested that you go for B.Com only. See if you get B.Com honours then its good else regular B.Com is also fine since you have that CA tag alongside.
Also, just for you to think, if at all you wanna go for correspondence graduation, I would suggest have a look at the ignou collaboration with ICAI wherein you have to give less papers to get your B.Com honors degree.
Think wisely, decide accordingly.
All the best.
Feel free to revert in case of doubts.