I have two questions regarding khums. If one is in dept, is it obligatory upon them to pay Khums? And who do I directly give my khums to for them to distribute it out?

Firstly you need to clear all the debts you have.
Once you have cleared them out, you can keep a calendar for your annual khums date and give the 20% of your annual savings towards the sehme imam and sehme sadat through the wakil of your marja that you follow.