Building a home is a full time job, starting a business is a full time job, and when you add the hours spent homeschooling and parenting THAT is a full time job.
Are you a single parent or do you have a partner? Will your brother be your full time partner or a source of part time help? I can just see 2 full time people who also work at the project on weekends accomplishing all that, but as a single person? That sounds like way too many hours.
I once attended a farm show, and I asked a speaker how I could learn to sell when my skills were in my hands. His reply was to take a job in sales, as the basic technique was the same regardless of what you were selling. Well there was a recession on, and I could not find a job in sales, and so I visited a popular nursery, found the person who was assisting the most customers, and I watched her out of the corner of my eyes, and then I practiced in front of a mirror. THEN I started selling at Farmer's Markets for the experience.
Tell me, since you wish to sell your produce, have you ever sold anything or is this also a skill you need to learn first? I learned a LOT from watching that sales lady!