What’s Shana Rishona about? Should it be spent in Ramat Eshkol/Yerushlayim on the parents’ tab?

What’s the source and reason for having a Shana Rishona?
What are the halachic requirements? How should the year be spent?
What are common issues that come up?
What preparation can be done to make a Shana Rishona easier?
What are the basic halachos of kavod to in-laws? What should in-laws be called?
How does a new Kallah properly interact with her new brothers-in-law?
How does a new Chosson interact with his sisters-in-law?