The location of your community folder will depend on where you installed the simulator to. If you installed the simulator to the default location, the paths will be as followed:
Microsoft Store/Xbox App:
C:\Users\YourUsername\AppData\Local\Packages\Microsoft.FlightSimulator_8wekyb3d8bbwe\LocalCache\Packages\Community
Steam:
C:\Users\YourUsername\AppData\Roaming\Microsoft Flight Simulator\Packages\Community
Retail Disc:
C:\Users\YourUsername\AppData\Local\MSFSPackages\Community
If you've installed the simulator to a custom location, you'll need to navigate there manually. As an example, if you installed the simulator to a folder named "Flight Simulator" on your G:/ drive, the location will be as followed:
G:\Flight Simulator\Community