Are you planning to release it on the App Store? It's a good concept, but I honestly don't see it succeeding due to many factors ranging from the built-in ads to the user interface.

There are a multitude of parking spots here in Egypt, (both legal and illegal), I'm afraid the app cannot document each and every single one.

Two alternative approaches could be you contacting owners of certain garages (that can park 'x' vehicles) all throughout Egypt and paying them a monthly fee for allowing you to make money through the app (eg: 10 LE per parking spot). Using the user's location you can find out who parked where and notify users how many parking spots are available in the garages around them. If this business plan becomes successful, purchasing and owning parking spots with 1 employee per garage/area would be the best way to go.

If the app gains recognition, more marketing can be applied by implementing this feature in an app like Google Maps (like what Uber/Careem did).

Best of luck.