Where can I buy a snack vending machine?
go to http://jordanvending.com/ they sell all kinds of vending machines.
Where can I find sweet potatoes?
@Virgin Megastore @Sameh Mall but maybe you'll find better quality in the nearest veggies store (y)
Where can I find a supermarket that sells Gas bottles?
Well, for safety issues its illegal for super markets to sell gas and such. you can always get gas from the nearest gas station :)
Where can I find an outdoor place for a wedding?
check out @Zuwar they have a great venue for out door weddings
Where can I take the course: Oracle (EBS) Human Capital Management Essentials?
I dont know if you can find the course in Amman but you can check out udemy there's a course for $10.
https://www.udemy.com/courses/search/?q=oracle+ebusiness&src=sac&lang=en