K.J.
Especially with a child that age, I would take an "unschooling" approach. (I do not have any particular references, google it.)
I think of unschooling as being what good parenting looks like. Take your child with you as you go places and talk about what you see, hear etc. Go to the park. Go to the library. Visit museum-- even museums you may think of as being for adults.
Even at home, be engaged. Dance together, read together. Follow the child's interests and some of yours. Play with blocks, bake cookies. Watch the nature channel, or the science channel...
My daughter found a beautiful mountain meadow of flowers with her 3-year-old, so they got a flower identification book at the library and learned that they were "marsh marigolds".
Say "I'm going to read my book. Would you like to get your book and read too?" or "I want to write grandma a letter, do you want to write one too?" "We need to do the laundry today. Will you put all of the white clothes in the washing machine while I separate the other loads?"
Math is very natural in the kitchen. "Look, the pizza had 8 pieces. I had 2 and you had two, let's count how many are left!" and "Look! I think we still have 1/2 a pizza for tomorrow." Look at kids cookbooks (with lots of pictures) and decide together what to fix for lunch or dinner.
Most children who have not been to school have learned many things and enjoy learning more!