If I change my internet service provider will it change IP address?

Yes - each mobile provider or internet service provider has a different range of IP addresses they use. If you change providers, you are changing networks, and your IP will change. If you absolutely need to have a stable address, the best thing you can do is get dynamic DNS which you can configure to resolve to your device whatever the address is.

Your IP address changes every time you connect to a different connection unless you've manually set it to static which usually isn't something mobile devices allow you to pick and choose. And a static IP address isn't something I'd opt for it present potential security problems and network problems.

Yes, each time you connect to a different network you get a new ip address. If you go to a friends house you're going to have a different ip than at home.