Forward after login to home page (success) and back to login page (failure)

I have been all over the forums and can’t find anything that works. We would simply like our login form to go to a secondary page upon success or remain on the login page on failure. I thought this would be simple. Right now, the form goes to the admin area upon success and to the wp-admin login upon failure. Why would I send my users to the admin? How do I over-write that?
I see the arguments for wp_login_form but don’t see where I’m supposed to change the redirect. I tried functions.php but that did not work.