He had his own crowd of friends as a human, so when he started phasing and hung out with Jared and Sam, his distance from his previous friends attracted some attention. Sam has to constantly be near him to make sure his accidentally-triggered transformations didn't attract notice from the locals - which happened frequently. As a shape-shifter, he sets protecting La Push and the Quileute traditional lands as his job.
She was devastated by her mother's death, and by the time she graduated from high school, she moved away to attend college to escape the pain and rarely visited her family. Upon graduation in 2006, she went back to La Push to visit her family. Originally intending to move to Seattle as soon as she found an apartment, her plans changed when she met Paul for the first time after his phasing.
Sometime in between Eclipse and Book 2 of Breaking Dawn, Rachel and Paul walked down First Beach alone. When they stumbled across each other, Paul imprinted on her, and later told her everything about their tribe's magic and heritage.
She accepted his explanation and reluctantly decided to stay in La Push for a while to see how their relationship will work out - and hopefully waits for Paul to be able to leave with her someday. Billy is happy to know that she has decided to stay for Paul, though he is always at their house, eating their food, taking most of their sofa and using their TV, which annoys them very deeply. However, Paul has gotten better control of his anger, due to his promise to Rachel to someday quit the pack and leave with her.
There is no mention of their relationship or how they progress after Book 2. However, after the Volturi confrontation, Paul is able to return to his struggle to gain a better self-control.