Tom woods has a great website full of homeschooling resources.

Obviously these things are aimed at kids older than yours, but yours are also always getting older.

https://tomwoodshomeschool.com/

The Waldorf methodology of teaching seems to me to be the best method for homeschooling as it allows for teaching while accomplishing tasks that need to be done around the house/farm/homestead etc. (I went to school to become a teacher, then dropped out as soon as they said that "diversity" classes were required to get the license). Teaching principals through action rather than theory on pen and paper.