Try finding a good Nissan sunny from 2004 to 2010 Japanese manufactured.You will get them for as less as 5k to 10k. Maintenance is very cheap. I am driving one and i can guarantee you will not regret. But, have a good mechanic check it for engine and transmission issues before buying. There is nothing else to worry about Sunny's.
Reason for Nissan sunny - its summer and AC cooling of these sunny's are unmatched. Ride and Handling are good. Since you dont know roads now, having a small built car will be better to navigate.
Advise - Do not spend a lot on car since you are new to Qatar.
Other option is as mentioned by Achabacha but getting Toyota cheap will be difficult.