35 min layover

My partner and I are pretty new to traveling and are looking at booking a flight from LEX-CUN which has a 35 min layover in CLT. We’ve only ever taken direct domestic flights, does anyone think this short of a layover is doable for an international flight? The plane flying into CLT from Lexington is an airbus319 and the next flight is an airbus321, so I have no idea if these will be at the same terminal. We will only have carry-ons if that helps. There’s also another flight with the exact same course a few hours later in the day. So if we miss the connection flight, would AA move us on that one for free if there are open seats?