Hello student,
After completion of 12th In Commerce ,these are some courses you can go for...
B com,BBA,BMS,BFA,BCA,also you can go for CA,You can go for integrated law course,and many more other courses.
After a successful degree completion,there are various career options/ job opportunities are as follows:
Chartered accountant,company secretary,cost and management accountant,bank officer,teacher,professor,
You can be in the managements
You can be a CEO,CFO of any of the companies,
you have finance department in every industry you look into and many more other options also
See,You have wide career options awaiting you.
But everything depends on your interest regarding this field
You need to discover yourself and find your interest first and then follow what your mind says.

Hope this helps

Good luck