For the first you have to make your stories.

The story should have title and a text.

A few basic advises:

1. Make short stories – no longer than 2 minutes (approx. half of the page).
2. Use spoken language, its more lively and entertaining.
3. Avoid too many dates and figures (no one will remember exact dates anyway)

Experiment with different approaches – stories can be build as monologue, dialogue or even as a story being told by the object of art itself or character from the painting.

At the Academy web site there is available course “Storytelling” discussing different aspects of storytelling in details and with examples.