How do you farm on Human age

Go to your home. Once in your home click on "Farm". In the top right corner you will see a sign that says "1/8 = 0 places". If you click on the plus buttom next to it, you will start to build your farm. Build it until you have 1 or 2 places.
Now you can buy ann egg, just click on the plus symbol next to the egg picture and you will start to incubate an egg. (An egg costs 10 kneecaps). Wait a few days until it hatchs.
Once your animal has hatched, you need to feed it, in the same way you do with your human. Wait till it is big enough to slaugter it and eat it.