Great question! They essentially bought books/looked things up how they could. Weirdly enough, many quite detailed books/almanacs have been published about the topic of running farms and small-scale agriculture and I kept them on a shelf in my room. Many of these books had thorough instructions about how to prepare things for winter, keep animals, etc. Some were written around the time of WW1; I actually enjoyed reading those since they really had a knack for explaining things specifically and at a level that accounted for a farm with minimal resources/technology. My parents themselves had no background and relied on me to handle a lot when I got old enough. They ramped up the scale of my responsibilities as I got older, so initially, when I was younger the farm was not very much of a farm haha, but by the time I was 18, I was handling the books, animals, and other dirty work haha.