Hi Angie, welcome to a2k. Someone with a little more experience will weigh in here and tell you exactly what the problem is. You may want to look at the topic called Avatar Tutorial
Avatar Tutorial
The picture under your name is the avatar. If you don't pick an avatar from the a2k collection, you can type in a URL of another avatar or picture from elsewhere on the internet, which is I assume what you did. Maybe the picture you picked was on a site that does not allow linking, or maybe it was too large - there are size restrictions. This has happened to me several times.
As for the lines in your signature disappearing, I haven't heard of that one before, and it has never happened to me. We'll have to wait for an expert to get the story behind that one.