BCA

Go through the list of top colleges and study their admission requirements :
https://www.shiksha.com/it-software/ranking/top-bca-colleges-in-Delhi-ncr/96-2-0-10223-0.

You can refer https://www.shiksha.com/it-software/colleges/bca-colleges-lucknow.

Yes, you are eligible to apply.

Pursuing two degree at the same time is not valid, Hence, it is better to go with some integrated programs instead of doing such degrees.

You will get this in Physics. Of course, there is no direct role of Chemistry in BCA. Students without Physics and Mathematics in class 12th are allowed to take admission for BCA. However, choosing the Science stream after class 10th would be the best option if you want to pursue BCA after school.

Yes, you are eligible for MCA as you are Bachelors now. It doesn't matter if you have done graduation from distance or regular mode.
All the best.

Yes, you can do B.Ed after BCA. Top universities and colleges providing this course are:
RVS College of Education, Coimbatore
Dr. NGP College of Education, Coimbatore
Rajlaxmi College of Education, Chennai
Madhya College of Education, Chennai
Jamia Millia Islamia, Delhi
Guru Gobind Singh Indraprastha University, Delhi

Hi,
Yes, you can do B.Ed in computer science. Eligibility for B.Ed in computer science:
The students who wish to get admission into B.Ed in computer science must have successfully completed their high school /10+2 or equivalent exam in any stream from any recognised board. The students are also expected to achieve a minimum of 50% aggregate marks in their final exams of graduation.

BBA, then MBA will have more scope as compared to BCA, MCA. Rest, opt for the courses that you love the most and are most passionate about, and analyze the future work conditions, scope and growth prospects before taking admission.
You can also opt for psychometric test comprising of Aptitude, personality and career interest to clear confusion.