From the looks of things, some page is trying to load your functions.php page directly. I’m not sure if it’s another part of your theme, or a plugin, or some other custom code. But the error on line 14 is triggered with a second <?php opening tag in your functions.php file.
This headers already sent error is triggered when you send any additional whitespace, line returns, or text when you’re not supposed to. A short-term fix is to remove the extra markup:
<?php // sidebar functions
if(function_exists('register_sidebar')) {
register_sidebar();
}
// portfolio functions
add_action('init', 'create_portfolio');
See how much more compact that is? No extra white space between ?> and <?php either.
For the long-term, though, you need to narrow down exactly what you’re doing. Where are you uploading the image from? Why is it trying to redirect to your functions.php file? Answer those questions and fix whatever problems are causing the issues for a more durable fix.