Nena, the title under your name is your title (nothing to do with your kitten
). Users with up to 20 posts have the title of kitten, 20-100 posts are young cats, 100-300 are adult cats and over 300 are alpha cats.
The only way to change thay is reach 1200 posts, when you'll be able to choose your own title
As for the little picture, it's called an avavtar. Go where it says user cp at the top of the page and in the menu click Edit Options. On that page, scroll down to the bottom - the last line says "avatar". Click there and you'll get to the page that let's you choose an avatar or upload one of your own.
Hope this helps - if not, please let me know!