What kind of potential energy are there?

Answer 1

Here are a few:

• Gravitational potential energy, defined by the height of an object
• Elastic energy, e.g. the energy stored in a stretched rubber band
• Chemical energy
• Electric energy stored in a capacitor
• Nuclear energy

There are probably a few more, which I am missing. I suggest checking the Wikipedia article on potential energy for more information.

Answer 2

I believe there is only one. But it can only happen to something extremely small and in small actions.