The MB to which the OP refers has the model number W202; it will have a torque-converter automatic transmission.
I agree with much of what "avocet" has written but have the following thoughts based on my own experience of an MB with a 'torque converter'.
I had a W203 with a torque converter and covered 198,000 miles with no problems from the torque converter, admittedly with many long journeys. Also, I manually shifted the gears only when necessary for overtaking or going down steep hills (IMO this prolongs the gearbox life).
If I was going to stop for more than a few seconds, I put the transmission in neutral; if this was in daytime, I put my foot on the brake pedal; if it was night-time, I used the parking brake (to avoid dazzling following drivers).
By putting the transmission in neutral, the ATF is not subjected to unnecessary use and this prolongs it's life. (NB: A torque converter and gearbox should be serviced in accordance with the manufacturer's recommendations, including ATF change and filter change; this is often overlooked.)
The parking brake (the small pedal that is pushed down with one's left foot) mechanism on an MB is a maintenance headache (I know this because I paid the bills time and time again) and I always avoided using it except when necessary.
If the car is stationary in Drive and held on the foot brake (not the parking brake), there is a risk of the foot slipping off the brake pedal if the car is 'rear ended'; also, sitting in the car with the foot pressed on the foot-brake causes back pain if the driver is prone to it.
If the car is stationary and in Park, there is a risk of damage to the gearbox if the car is 'rear-ended).
Finally, regarding the OP's other comment, a torque converter (and probably DSG and CVT), should also be put in Park (not N) and the parking brake / handbrake applied before opening the driver's door. This was not done by a driver a few years ago (the car was in N), and the car rolled back and killed a passing jogger (it was on the south coast somewhere and no doubt some forum members will remember the full details).
I agree with much of what "avocet" has written but have the following thoughts based on my own experience of an MB with a 'torque converter'.
I had a W203 with a torque converter and covered 198,000 miles with no problems from the torque converter, admittedly with many long journeys. Also, I manually shifted the gears only when necessary for overtaking or going down steep hills (IMO this prolongs the gearbox life).
If I was going to stop for more than a few seconds, I put the transmission in neutral; if this was in daytime, I put my foot on the brake pedal; if it was night-time, I used the parking brake (to avoid dazzling following drivers).
By putting the transmission in neutral, the ATF is not subjected to unnecessary use and this prolongs it's life. (NB: A torque converter and gearbox should be serviced in accordance with the manufacturer's recommendations, including ATF change and filter change; this is often overlooked.)
The parking brake (the small pedal that is pushed down with one's left foot) mechanism on an MB is a maintenance headache (I know this because I paid the bills time and time again) and I always avoided using it except when necessary.
If the car is stationary in Drive and held on the foot brake (not the parking brake), there is a risk of the foot slipping off the brake pedal if the car is 'rear ended'; also, sitting in the car with the foot pressed on the foot-brake causes back pain if the driver is prone to it.
If the car is stationary and in Park, there is a risk of damage to the gearbox if the car is 'rear-ended).
Finally, regarding the OP's other comment, a torque converter (and probably DSG and CVT), should also be put in Park (not N) and the parking brake / handbrake applied before opening the driver's door. This was not done by a driver a few years ago (the car was in N), and the car rolled back and killed a passing jogger (it was on the south coast somewhere and no doubt some forum members will remember the full details).