It seems like you’re trying to post images. I’m afraid there are strict guidelines for what pictures can get posted on the forum, so there are some restrictions on who has that ability.
You can read more about the photo guidelines in The Great Big Photo Guide, and how to increase Trust Level in Trust Levels. But the short version is that you’ll need to participate in the forum more, and get a feel for what images are allowed and where, before you gain the image-upload perk. 