Usually on Pinterest there is a button in the upper left corner that says "web site" and will take you to the original site that had the picture.
In my opinion, Pinterest isn't really a social media site; it's more of a visual bookmarking tool. Sure, you can share stuff and follow other people, but there's not a lot of interaction between people. If that's what you want, Instagram is probably more what you're looking for. Pinterest will bookmark pictures, which I like because I'm a visual person. It's easier for me to look at pictures to find a quilt or a tutorial I bookmarked, rather than to try and remember the name and search for it in a list.