So I'm kinda confused about the whole Padme thing.How is she both reyna Amidala,and her handmaid Padme?Also in episode III she dies in childbirth,but in episode VI Leia talks about having known their mother?

She served as reyna of the Naboo in Epi.1 her decoy and handmaidens are all lookalikes. In the movie Kiera Knightly is the one dressed up in the Queen's lavish uniforms pretending to be Padme while Natalie is one of the handmaidens and the real Padme.

She does die in Childbirth. That was a small plothole when Leia sinabi she remembers her mother as being "very beautiful but very sad"- though like her father she could have had nightmares and visions of her mom in her sleep.