yes
The Question and Answer section for The Fault in Our Stars is a great resource to ask questions, find answers, and discuss the novel.
yes
Augustus uses his wish from The Genie Foundation, an organization that grants one wish to cancer kids, to get Hazel, him, and Hazel's mother a trip to Amsterdam.
Check this out, I'ts a good introduction to the book:
https://www.gradesaver.com/the-fault-in-our-stars