Everybody used to homeschool preschool. And you still can. Get a preschool workbook from just about anywhere and pair it with lots of hands on fun. Everything from alphabet games, puzzles, and activities to cooking in the kitchen with dad. Then add in a once-a-week play group with other little ones.
To be ready for 1st grade kids should know the ABC’s (identify the letters and sounds), be able to count to 30 or higher, be able to identify the major colors, identify the basic shapes, and have been read to lots and lots.