You will start out with The Hoe. Should you lose it, The Hoe can be purchased from Pitchfork Jeb's Farmer Supply The Hoe is used to till the soil, in order to be able to plant seeds. To use The Hoe, equip it, and you will notice the area under your cursor changes to a lighter color. To till that area simply left click. To turn tilled land back into grass, plant Grass Seeds. In addition, you can remove any stone paver with it.