Sometimes a person can score a free piano and everything works, maybe makes a few creaks and clicks, doesn't hold a great tune but can still have fun with it if that's all your looking to get out of it.
If you're going to take lessons and seriously want a reliable instrument to practice on, I'd keep looking. If you're looking for something that works ok, you won't get too frustrated everytime an action part breaks, just want to set your drinks on it in your man cave and belt out a few tunes with the fellas, sometimes an old clunker works out. Make sure those fellas help you move it in AND out of the house and you can pay for the case of brewskies.
One more thing....re: terribly out of tune, that's usually a sign of neglect right there.