Open Graph adding meta

Here is a question from a beginner.
I need to add open graph tags to be able to share correctly with facebook. I have tried EVERY PLUGIN but noting works and I used Firefox web developer tools to understand the codes. I have read http://ogp.me/ in detail. I have surfed the net. Two weeks now – every night – no progress. It might be because I’m just stupid.
My webpage (www.swedishpunkfanzines.com) has both pages and posts. How do I mark for each page which is the image to be used as tumbnail for open graph and how to I add the description. It seems that the title is correct and the page as well when I share link to facebook (or other does). I have used the facebook debugger.
There is most likley a lot of missing info – including beeing an code idiot but I’m trying really hard.