Will my phone work at all in Costa Rica?

I'm going to be on vacation in Costa Rica for a week. I have an iPhone 7 through US Cellular and I was wondering if I'm going to have any sort of service down there (as in data or voice). We will also be switching hotels almost every night while we're down there so will most hotels there have Wi-Fi?

Many have Wi-Fi. Is it FREE. Not usually. It can be in parts of the Hotel.
There are tens of thousands of Hotels. THEY ALL do not have the same stuff.

http://costa-rica-guide.com/practical/phones/cell-phone-coverage/
Cell phone coverage is not EXCELLENT everywhere.

Some reason in particular you can't ask the particular hotels you are staying at?

Have you found out what you cell phone company will charge you while in Costa Rica. Too many plans to tell you what the charges may be.