Here’s one way to fill in the blanks:

I have a very interesting and (1) **enjoyable** hobby. I make short video clips with my digital camera. It was my birthday present from my parents last year. Since then, I have (2) **made** three short films. It's great fun! I started asking my friends and relatives to take (3) **part** in the films. I have tried to write the story for my video clips. When I have finished the script, I make copies for the "actors." Each scene is small and they can look at the words just (4) **before** we start filming. We film at the weekend.

So the completed sentences would read:
1. enjoyable
2. made
3. part
4. before