Although I didn't grow up on a farm, I come from many generations of farmers and my Dad grew up on a farm. As such, I grew up on five acres of homesteaded land (e.g. large garden, poultry of all types, orchard, beekeeping, food preservation including dehydrating, freezing, water-bath canning and pressure canning)
I'm now in the process of spending every spare hour I have when I'm not working at my "day job" to not only expand our home garden but also develop 20 acres into an organic farm.
Amy Stone puts it very well. Homesteading/Farming is extremely hard work and intensely physical. Even food preservation in the kitchen after harvest time is a full time job of itself in the prep work and processing. As Amy Stone said, you really have to love doing it and you have to enjoy exhausting work.
Yesterday I worked in a field planting around 4,000 organic sweet corn seeds in 90+ degree Fahrenheit heat and full sun. Although I was able to make the rows with a tractor and I was able to use a walk behind seed planter, I had to cover the seeds in each row by hand with a hoe. Each row is around 200 feet long and I planted 15 rows yesterday; that's over 1/2 mile of corn. Next week I plan to plant another 15 rows the same way. The week after that...another 15 rows the same way. This is all in my free time at this point.
How do I learn? I do a lot of research on my own in the evenings including reading, internet sites and watching Youtube tutorials. I learn by doing (trial and error) and I also enrolled in a farm business management program through a community college. That has been very helpful because I have a farm instructor that comes out to our site and teaches me one on one.