If you have a GCC driving lisence or Brittish, American or Canadian,
They will automaticaly give you a Qatari one directly (just do the eye test),
Other wise if you have any other type of DL then you apply and see what they want from you.
If you do not have any DL then they will ask you to go to a DL school first.
in all casses you need to pass them by in Madenat Khalifa take what ever DL's you have

Best of luck