can anyone explain how to use the words forget forgot forgotten in a simple way

I'm afraid this cannot be done in a simple way. This will help you on your way:

Forget (infinitive verb, present tense, imperative verb)

- I want to forget it.
- I always forget it.
- Forget it.


Forgot (past tense)

- I forgot it.

Forgotten (adjective and participle)

- The forgotten world.
- I have forgotten my password.


If you need to look up any of those terms, you can search Grammar Monster here. They are all covered with examples.