IPhone still works but screen is black?

Around the beginning of the week, I tripped on the stairs while I had my iPhone 4s in my hands. The screen cracked but everything was working fine. Last night, I was going night swimming with my friend. I have two decks in my backyard, one attached to the pool and one attached to the house. I left phone on top of my towel on the deck that attaches to my house. When my friend had left, I went to get my towel and my phone but when I did I realized that there was a bunch of condensation on it. I think some of the water got in the cracks and now the screen has gone black. I can hear the noise it makes when I plug it in, if I press the home and power button I can hear the screenshot noise, and if one of my friends text me I can hear the noise. I tried unlocking my phone but I can't because I have a passcode. I looked up what to do and tried multiple things but none of the work, I don't know what to do! If I take it into the shop, will they be able to fix it or will I have to get a new one? Is there any way I can fix it at home? I'm 13 so I don't really have much money, so I can't pay to get it fixed or to get a new one. Someone help!

Try restarting it by pressing the home button And the power buttom at the same time