You should be at least 18 years of age to be able to drive in Belgium, even if you are allowed to drive in your own country and have an international driving license.
You should have an international driving license or permit to be able to drive in Belgium. If you have European license, that should also be enough. However, being an international visitor you should have an international driving permit that is valid for a year.
You should know different speed limits for different roads. The speed limit for rural areas is 50 kilometers per hour (KPH), for areas near schools, it is 30 KPH. On national roads, it is 70 to 90 KPH and for highways, it is 120 KPH. Exceeding limit can land you in trouble with law.
Make sure the car you are taking on rent have an insurance cover. Driving a vehicle without license is not allowed and you should not even think of that. There is huge fine and other penalties on driving a vehicle without insurance.
The vehicle you are going to drive should have proper registration with local vehicle registration department. It should display the local registration plate and you should carry registration documents with you.
Make sure that your vehicle has fitness documents. Driving a vehicle with some defects is illegal in Belgium and you can land yourself in trouble with law in that case. The vehicle might also be confiscated, although you might get away with, if the vehicle has been rented out and you do not know of the fitness details.
Traffic and Safety Rules
In addition, you should observe all safety and traffic rules and guidelines. For example, wear safety belt while driving and secure your children properly in the vehicle. Also, do not attempt to trespass the traffic signals or commit violation such as overtaking another vehicle in the restricted area. Make sure you also display parking sticker on the vehicle at the time of parking it in a charged parking area.