A parking fee is what you pay to park your vehicle in a designated lot or garage instead of on the street. Some places have assigned parking spaces while others operate on a first-come-first-serve basis.
Depending on how your apartment operates concerning parking, it might be worth it to pay a parking fee. Paying a fee could get you a better, more convenient spot closer to your building and it could guarantee that you have a space in which to park, instead of having to hunt for a spot on the street or in a free parking lot.
Parking that requires a fee will usually have better security, so your car is less likely to be vandalized and you'll be safer walking to and from your car. But parking fees can be expensive and add up quickly.
Most lots and garages will still have limited spots in which you can park, even if you're paying a fee. And you're still sharing those spots with other tenants, so problems may come up, especially if multiple people are competing for a desirable spot.
Your apartment complex might have a free parking lot available for tenants, but it might be further away from the entrance to your apartment or it might be crowded and difficult to find a spot.
You'll have to decide if it's worth paying extra to have a better parking spot that's close to your building.