Water damage cannot be repaired, a replacement phone is needed. If you don't have AppleCare+, you may have to pay the full replacement cost in case of serious damage, but this is a recent change in wording. Water resistance is not the same as water resistance. In any case, the fall may be the culprit here and not the water.
In any case, I suggest that you make an appointment with the Genius Bar at your local Apple Store or at an Apple-authorized service provider to have it reviewed and given you your options. If you chose to sign up for an AppleCare+ plan when you purchased this phone, this could be one of two accidental incidents, and any repair or replacement should have a reduced cost. I know the difference between water resistant and water resistant. Anything that's remotely water resistant should have survived this fall, but fine.
Sorry, I didn't want to admonish you, but you'd be surprised how many posts we have here where people don't. Or you feel that Apple is deceiving about the differences. Here we don't even talk about repairs done by yourself or by third parties. Apple simply won't try to repair an iPhone in which liquid detectors, such as those in the SIM tray, are turned on in red.
Big mistake, the newly purchased iPhone 11 pro had problems and after 2 months of dealing with Apple, they shipped a new iPhone 11 pro. Unfortunately, there's not much you can do to repair damage caused by liquids inside the screen itself. If the damage to the screen is significant, use the appropriate repair guide for your phone to replace the screen. Thanks to the waterproofness, you can expect your iPhone to work well after diving, but if you have any problems with your iPhone in the future, the incident may come back to haunt you.