It is in a language I can't read

You'll need to tap Settings, then tap the "general" section. Since you probably can't read what it says there, it has a smaller icon that is identical to the main Settings icon on the home screen. Scroll all the way to the bottom. Tap the second to last button. Then tap the first button. English will probably be listed as the second language.

Once you've reverted to English, you may need to change the keyboard. Simply go through the above procedure until you see the keyboards tab. Then select or deselect the one you want.