Information Technology

Yes, you can do BCA after 12th. But for BCA maths is compulsory.

Yes, CSE is a good course to do and you can see yourself growing in this field. If you are asking about private colleges you can follow the given colleges:
Indian Institute of Technology, Delhi
Netaji Subhash Institute of Technology
Delhi Technological University
Indraprastha Institute of Information Technology
Maharaja Agrasen Institute of Technology

Visit the Shiksha link given below to get the placement details of all the colleges in Lucknow:
https://www.shiksha.com/it-software/colleges/bca-colleges-Kanpur

You can consider following colleges:
Harcourt Butler Technological Institute, KanpurKamla Nehru Institute of Technology, Sultanpur
G. L. A. Institute of Technology and Management, Mathura
M. Engineering College, Gorakhpur
Krishna Institute of Engineering
Institute of Engineering and Technology, Lucknow
Ajay Kumar Garg Engineering
Shri Ram Swaroop Memorial College of Engineering

After 12th, you can opt for BCA for getting job in software.

Fistfull to do MBA:
You have to be eligible for that and to be eligible for MBA you need to do your under graduation so you can choose BCA or BBA to complete your MBA BCA has good scope but for that you need a good college check out some good colleges for yourself and pursue your BCA or BBA to study MBA because you don't have very good marks. Still, you have a chance to get a good college if you can clear the entrance.
Good luck.
Thank you.