If you follow my advice, at least while you are just starting out, you might find this less frustrating. As your pages grow in complexity you are going to have many more elements to manage.
The way your code is formatted, I can see that it would be hard to tell which are the matching pairs of open/close tags. If I work my way down, I can see that your first column is missing its closing tag. Your second column begins before the first one is closed.
That error message is not very clear, the code checker is not very smart. It is counting your divs and looking for that image file in the second column but since the first column didn't get closed it can't cope.
About that bit, almost all HTML elements have both an opening and a closing tag. When you start a new element, you might as well type both tags right away.
Please ask anything that you have doubts about.