Seriously, I didn’t know that. I found this.
Caboodle has a complicated history. It’s been spelt down the years in many different ways, and these days is usually listed in dictionaries with an initial “c”. It means a collection of objects, sometimes of people. It commonly turns up in the whole caboodle, meaning “the whole lot”. It’s recorded in the US from the middle of the nineteenth century. It’s probable that the word was originally boodle, with the phrase being the whole kit and boodle, but that the initial sound “k” was added to boodle for euphony.