Hi. I REALLLLLLY want to post pics of my families but have no idea how! I am using a mac but when I click attach picture it says " Enter the complete URL for the image you wish to display."
What do I do?

The "Image" function is for displaying pictures that are already uploaded to a site somewhere on the Internet. If you want to attach your pictures to your posts, you will need to use the forum's File Manager. I've provided complete instructions for posting pics here.