How to get my iPhone to work?

S we were in this float that holds about 6 people in it and had two coolers and my iPhone had its lifeproof case in which it's suppose to be waterproof, well my phone ended up dying and when we were heading back to shore I grabbed my phone and my flashlight was on but my phone was dead, so as soon as my mom got back from getting my friend I charged my phone and I couldn't get the flashlight thing to work it was still on this morning and finally had turned off but now it doesn't work, so we get home and my phone is working perfectly fine, I ended up taking a 6 hour nap and now I have no service, but my internet works

Added (1). I also received a notification about my SIM card I don't exactly remember what it said something probably along the lines of SIM not readable or something like that

Try leaving it in a bag of white rice, while off, over night. The rice should suck out any remaining moisture which could be causing issues. If that doesn't work then try doing an erase and reset of your phone.

That sucks

Do you have an iCloud or iTunes backup? If so, try doing a hard reset on your phone and for good measure, go into Settings->General->Reset all content and settings. Agree and wipe your phone, then restore it from your backup. If that doesn't work, it's not a software issue and you might need to bring it to a technician to find out what's going on and how it can be fixed, if at all. Hope that helps!