How are stars created? Do stars last forever?

1. They are born from other stars.  They do not last forever.  They last until they have a baby.
2. A star starts as a cloud of mostly hydrogen and a little helium and some heavier things.  It collapses and gets hotter.  Hydrogen is turned into helium by nuclear fusion.  And then you have a star.  Stars do not last forever.  They start to break down recycling to make new stars.

(The first answer the child learned from a TV show, the second came from research)

Why is water blue in the ocean or in a pool, but clear when it’s on you?

The water does not have any color.  In pools it’s the bottom of the pool that’s blue.   In the ocean, it’s the reflection of the sky.