Hi roula230,
After your iPhone was dropped, we understand it's no longer connecting to a Wi-Fi network nor your cellular network/data. We'd like to try and help. We suggest following the steps in this article: If you see No Service or Searching on your iPhone or iPad There may be some steps you're unable to perform such as checking carrier settings and updating the software but we ask that you follow the other steps including taking the SIM card out and putting it back in. While the SIM card is out, check it for any dust, debris, or damage.
With not being able to connect to a Wi-Fi network, check out this article: If your iPhone, iPad, or iPod touch won’t connect to a Wi-Fi network We suggest trying multiple Wi-Fi networks to help isolate this.
If the steps above do not work, providing more information such as the exact error message, if there is damage to the device, etc may help get more answers.
Take care.