Commerce

Yes, sure. You can pursue B.Com as well as BBA.

There are many short-term Diplomas in commerce field, you can do Diploma in import and export.
Diploma in foreign trade.
You can learn other languages like German and French.
There is Diploma in taxation also. You can do that. Also, these all Diplomas are short-term and you can complete it in one year.
If you are interested in the computer field then you can learn computer language also.

Hi Shaleen, Being a commerce student you can choose accounts, finance and banking related programs which are in demand. But no course is attached with high salary package unless you are yourself great at it and skilled. So you have to know which course would suit you best, figure out your interests, areas of excellence, skills etc. You can check the SOL of Canada, every country has its skilled occupation list which displays occupation in demand.

Yes for preparation of civil services, it would be beneficial. But you continue with commerce that would be more beneficial for you.
Good luck.