does farm/planter need npcs to work on it? or npc just automate the process to seed and harvest it?
No, plants in planters grow just fine on their own. You can leave a plant for a long time, and it'll wither and produce seeds for replanting. Which is a good thing for soy, because you need soy seeds, not green soy beans.
Villagers are said to be magically speeding up plant growth. They also automate harvesting and replanting, but they seem to just emulate the way it should work, which can lead to strange results.
Breeding farms, on the other hand, need villager working on them. They seem to work with just 2 species: sheep (to produce wool) and cows (to produce milk). Cows can be ordinary or pink-colored, pink-colored are said to produce milk faster.
Pigs and chickens have their own dedicated buildings. Everything else you can put into a breeding farm as a decoration, but doesn't seem to produce anything.
By the way, pigs need villagers working on them, and chickens are fine on their own.
where do you find those muscular giant girls?
Those are "large female native". They are found in raids when you have flower totems to attract women, replacing large male natives that come in raids normally. Raids don't need to be high-level for them to come, but their favorite food is "fighter orbs" that drop from high-level raids.
The really tall woman (who is not muscular) is Giant, a unique NPC/boss you can recruit.
