1. I am about to take a heavy Student loan of 10 lacs within 2 years, so I am saving my money for it. Do I need to pay khums on that?

I do not have much assets, in future I will be working in my spare time to pay the loan.

2. For clothes, what is obligatory to to be done? Like I have a purchased a cloth and wore it for once just to see the fittings. What is the rule here?

1- There is no Khums on laon. It is not saving it is your debt.
2- Khums is wajib on saving not on expenditures.
It there is any unused stuff or gift or any saving then you have to pay khums on it.