It depends on your job place which will at first become your social circle. I think of Doha like a big college frat house but you'll be making more money and have more opportunities to travel. If you know the right people, there's a couple of parties every weekend. Parties happen at houses not clubs. The nightlife is a bit pretentious and always high end. There's only 1 or 2 places where its like a pub/garage bar.

I would not worry about the night life. Most new people should worry about their cultural transition and how much BS you can put up with (which hopefully is why you're paid alot to come here).

Good luck.