You might want to draw inspiration from your personal experiences or interests when naming your private story. Maybe there's a place, a hobby, or a special memory that could form the basis of the name. Or, try combining words that have a special meaning to you.
A name related to the content of the private story would be good. For example, if it's about your travel dreams, 'My Travel Wishlist - Private'. This way, it gives a hint about what the story might contain while still keeping it private.