Qatar Airways do interviews all around the place and the best way of finding out would be to contact recruitment at Qatar Airways. The address can be found on the web site.
I do recommend you try for EK or GF before you take a job with QR. They are a very hard airline to work for and that is not just the physical side of it. I never been put off by hard work but this airline pushes the crew to the limits as it does the aircrafts. They are excellent at ensuring the investments made are used to the fullest capacity.
Time off is often sleep time but rostering do not see it like this. they call on your day off and change your roster as often as they feel like it. call in sick and the next thing you know you are placed on very early stand-by shifts. In short, you get punished for being sick.
I have been to the beach in Qatar and could not help but to notice the amount of rubbish and dirt all around. so I do not believe the place has any beaches that could compare to those in Dubai. Dubai is fantastic with something to do all the time for every type of taste. Doha is a hole of a place with the same thing happening each day. shopping is good in the larger supermarkets but once you have seen it there is not too much more. Do think very hard about it. its not all bad as it is whatever you make of it. Make friends and keep them close or else you will go mad.
Enjoy your time.