Guide To Farming
First you'll need some supplies! In your crafting menu, you can find entries for a 'copper hoe' and a 'copper watering can'. To craft both, you'll need 5x wood and 7x copper. Check out the guide to mining to learn how to acquire the necessary copper ore.
Not all soil can be tilled. The most easily accessible soil can be found on grass tiles, but some areas permit tilling different kinds of soil too. It's recommended you only till soil around your established home both for ease of access and to reduce orphaned farms around the game world. With your copper hoe equipped in your weapon slot, press the 'x' button to till the soil in the tile adjacent to you that your character is facing. This action will require 100 energy per tile tilled.
Putting Down Roots
The agricultural vendors in major settlements offer a range of seeds to choose from. One bag of seeds purchased amounts to one plantable tile; so think of it as one bag per tile. Simply stand over the tile you want to plant seeds on, use the seed bag in your inventory, and plant away!
Watering Your Crops
It's important to water your crops to avoid decay! Always fill your watering can and keep one near your farm or in your inventory for easy access. Make sure your seeds are nice and hydrated!