Hello. I have completed by B.Com this year. But I'm confused. I don't know what to select and what subject I must select in B.Ed.

You can choose to do Masters and the subject concepts should be clear if you want to go for teaching job.

You can pursue B.Ed with english and social Science subject as you are a graduate but if in future you want to teach commerce students then pursue master as well.

You can go for any subject for which you feel interested, just be clear with its core concepts and knowledge.