Go to the Toy Box Hub. Talk to Woody, and he will load up a barn area, and ask you to collect 5 tomatoes. Get them, and then enter the door that appears. You'll have to go through the sidekick tutorial, which is straight forward and takes 5-10 minutes. Afterward, enter the door by the barn again, and select the second option (the one about farming or gardening). In here, woody will teach you how to farm. Go through his tutorial, and at the end pause and open the sidekick menu. Give each of your sidekicks the hoe, and place all of them. They will all start planting, and as weeds and flowers grow you can attack them to "harvest" them. It should only take 5-10 more minutes to get this once the plants start growing.