Twitch changed its interface and I can't find anything

Ugh, I totally get how you feel! First thing is to check if there's a bell icon or notifications somewhere at the top of the screen (usually top right), because Twitch moved that stuff somewhere else. For your history, check your profile (your picture or initial in the corner) and look for "History" or "Watch history" from there - sometimes they hide it in a menu you have to swipe through to see all the options. If nothing works, try logging out and back in, because sometimes that resets the interface and things show up where they're supposed to be!