Where do exhibitors and vendors rent their exhibition stand from? Is it provided by the event organizer?

It depends on the exhibitions.
So exhibition organizers only you let you use their stands/stalls with limited options for changes (less common), some refer you to a list of 'approved' stand installers/designers (fairly common), and others let you do whatever you want so long as you follow a few basic safety guidelines (and stay within your stand limits). For the last option, there is a wide variety of service providers.
I am in touch with an international stand creator - they create very unique stands, but they aren't cheap. If you have a high enough budget and are in the US or Europe, I could connect you.
Good luck