Hi,
I would suggest renting a car for the first few months as buying is a bigger investment and best to avoid in the first year. If its a car from the dealers then most often you have to pay a 20% down-payment, insurance, opening a salik account etc. or if its from an individual buyer then you have to get a service check done as well as check the car's history as well as any hidden issues with the car. Buying a 2nd car also means you are buying someone's problems :D
On the other hand renting a car is a much more safer and an easier option to start with.
I rented a car from Yzer Motors. I got a budget car as all I cared about was just a car that took me from point A to B :D They had luxury cars too if you prefer that. Overall the service was good and they were quite flexible in picking up the car and it was easy for me to extend the days as well. This is the link if you want to use them. [url=https://yzermotors.com/en/vehicle/rent'>link[/url'>
If you are lucky to be from the countries where its permissible to exchange your licence for an UAE one then renting a car it is!! Oh and dont forget the crazy taxi drivers on the streets. Safe driving!!
