I've read novels since at least 2nd grade and I honestly don't remember what my first one was... Maybe Just So Stories, a collection of short stories by Rudyard Kipling, was one of my earliest I still remember. I know as a young kid, I adored The Twenty-One Balloons by William Pène du Bois, which I'm sure was one of the first novels I ever read. It captured my imagination for what felt like a long time ((at least for a kid)) with its sense of adventure and the memorable characters. I haven't touched the book since childhood and yet I still remember the main character's name was William Waterman Sherman.