Repair water damaged iPhone

I had my phone get splashed on when I was in my friends hot tub yesterday. That night, the screen started glitching out and eventually, the screen got brighter and brighter, and brighter, and then suddenly, it’s stops working. What do I do?

What do I do about the water damage? I’ve never had this happen and I desperately want to know the steps I can take to get my phone fixed if possible.

[Re-Titled by Moderator]