J4,
At 22, you shouldn't be thinking even twice before joining QR. if you get it, just go for it. It's a good company for career progression and Doha is a decent place as all the veterans here have commented. But make sure you
and speak up only when needed.
As a second officer at QR, I must say your joining as one of the worlds best airline at right time. Qatar is progressing and will open up plenty of opportunities for fleet transfers and upgrades. But don't expect to be treated well. As always, high expectations leads to disappointment.
Good luck
