Can someone explain the rings as if I’m 5

I’m still a bit new to this so please don’t hate me 😭 Between the books, series and movies can someone explain who and how the rings were created? I read somewhere that in the books the rings weren’t even created with Mithril or saurons blood? Watching rings of power (finished season 2) so I’m so confused. Did they just make up how the rings were created for the series?

And the ring Frodo has in lotr movies is which ring?

Sorry again for sounding dumb af rn 😅