The book is over a hundred years old, so you'll forgive a few spoilers. There are actually two related stories here:
First, there's Mr. Bedford, who has no scientific training and mooches a ride to the moon with Mr. Cavor, where he plots all his business ideas and bludgeons scores of moon people to death with a solid gold crowbar. He goes home, a stupid little kid accidentally flies off in the Cavorite sphere, and that's that. Good times. Convenient how he, against the extremely long odds mentioned by the narrator, not only gets back to earth, but back to England.
Next, there's Mr. Cavor, who gets left on the moon more or less out of necessity, and perhaps by his own choice. The Selenites track him down, and begin to communicate with him. How inconsiderate of Mr. Cavor to make them all learn English instead of him learning their language, especially since they only have one language globally. Here we get into the book's social commentary, which Wells was always big on but which posterity has forgotten in favor of his science fiction elements. Is it truly by accident that Cavor mentions that he's the only way humans can get back to the moon, and that he fails to send earth his formula for Cavorite? Or is he conveniently trying to keep the indigenous peoples from being trampled down by the earth's world powers? Plus we have the Selenites' interesting social structure, like communism, to the extreme.
Reading this book for the first time in the twenty-first century, one's thoughts go like this: "Hey, Wells made some pretty decent predictions about helium and the moon…well, except for the moon plants…and the giant moon cows…and the moon ant people. Never mind."
Wells was a great writer, though, and this story is engaging and, early on, humorous. Seems like he was trying to outdo Jules Verne's From the Earth to the Moon and its sequel. The First Men in the Moon is over the top in this day and age, maybe, but in 1900 nobody knew any better. Well done, sir.
RECOMMENDED