Free Full Online Homeschool Curriculum options
While there are a few websites have all (or almost all) of what you need on their website, many of the websites also use books that are free to download or read online. Some require you to get a book from the library, and then others will have free instruction for a college or high school textbook that you would need to buy. While the latter is not completely free, the instruction is, which I think qualifies as a freebie!
Ambleside Online is a free home school curriculum designed to be as close as possible to the curriculum that Charlotte Mason used in her own private and correspondence schools. Ambleside Online recommends the highest quality of books and most of the books could likely be found through a library loan system. The curriculum also uses as many free online books as possible, and there is no cost to use this website or join the support group.