Planning and calendaring my days

HI HI HI! I realized through my thought downloads that I need to plan my days on my calendar so I can get all the things that I want to get done to fit into my life. I feel like am getting stuck because I don’t know how long the projects that I have scheduled will take! I also want to get so much done that I don’t know what all to schedule and will I be putting too much on my calendar that it will be sort of a downer when I don’t get to it all. Will I need to rearrange my days to fit them in as I go along or how does this calendaring/planning thing work?
I’ve never done it and I’ve heard you say you even have what your having for lunch the next day all planned out so you can save mind energy! I need more mind energy, I work from home with my 2 kids, 3rd is at school and I feel it’s a struggle to get all the things done that I want to get done during the day! ( I have a little business- sewing and selling childrens clothing on etsy and want to get more efficient and organized in my mind to do wife, mother, and sewing business better.)
Thanks for any suggestions!