Often the collectors are just as interesting as their collections. Providing a bit of background about yourself can help people understand your collections and make them more interesting. People will enjoy looking at your collections more if they know a little bit about you.
People visit Collectish because they're interested in looking at the Collections. So if you're having trouble thinking of ways to describe yourself, perhaps start by answering a few questions such as:
Go to your profile page and click on your Description. A dialog will open that will enable you to update it. Click on Save when you are done.