As another part to the tutorial quest line, you will find that you will be tasked with taming a Groffle for your new farm. In the crafting section of your journal, the first page would be for your adventurer set. In it will be the Celium Seed option, where you grind down a Celium Flower for its seeds. These seeds are the item you need to entice it to follow you, and given how bountiful the flowers are on the plains, you shan't be too stressed to finding the feed.
Make sure you also take the time to place the Large Animal Pen on the farm before trying this. Have the Groffle walk onto the farm land to give you the chance to adopt it.
* Do note: to adopt any animal, it must first be happy and following you. You can't try to push some animals onto the farmland as it won't count. Furthermore, you need an open pen for the animal you're trying. Most are small, but there are a few that are large (such as the Fluff Pup, Fenicorn, Girpacca, and Groffle).