I need examples of self vs. self, self vs. nature, and self vs. society in Pride and Prejudice, and the page number where I find it.
Since I don't know what version of the book you have, and I most likely don't have the same version, page numbers won't be the same for both of us. But hopefully if I can give you an example or two, it won't be too difficult to locate where they are in the book.
Self vs. self is demonstrated quite well through the character of Elizabeth. She rejects Darcy's proposal, and then, after the letter and several things happen, changes her mind. She struggles within herself; she is conflicted. She had awful feelings about Darcy, but as those feelings change, she beats herself up for having rejected him, and lost her chance to be with a man that she truly loves and respects.
Self vs. nature is more difficult, since this novel is about people and human relationships, instead of focusing on nature. However, take a look at when Jane goes to visit the Bingleys. Their mother sends her without protection over there when it looks like it will rain; it does, and Jane ends up very sick. Then, Elizabeth walks all the way over there, muddying up her dress hems, in order to visit. This independence and unique behavior sparks the interest of Darcy, leading to his affections for her.
Self vs. society is a big one, with many, many examples. Society would expect Elizabeth to accept Mr. Collins when he proposed. It was a good match, it would unburden Elizabeth's parents, and would establish her in a respectable household with a good income.
I hope that those examples help to start you thinking; good luck!