CA

Hello Diya,
I must say that you are thinking on correct lines. Commerce graduate have lot of choices. CA of course is the best option that you have chosen as your dream.
Best wishes.

Yes, there is no such restriction so you can do M.Com also along with your CA. However, M.Com does not have any advantage neither for any job in the corporate nor for any value addition on your CA exam. Mostly M.Com is done by those who want to make a career in teaching only.

Look don't try to get involved in more than one thing simultaneously.
That would affect your career too.
Try to focus on one thing only and do your best in that particular area.
Good luck

Yes, you are eligible for doing CA after completing your Bachelors in arts.

Prepare for the CPT Exam.

Other than CA and CS, you have ICWA and CMA which are also professional courses. You can do one of them. But you need to have patience and very hardworking.
Or, do an MBA in a reputed college after B.Com.
Or do M.Com after B.Com.

Yes, you can pursue CA programme, but according to me that will not a wise decision in term of total duration of programme is 3-4 years and you have to give full attention and time too for study to crack the exam.
In other case you can plan for MBA-finance that will be complete in next 2 years from good b-school and you can see your career with good growth and salary too.
Rest you can decide according to your career aim or interest.