When you start this adventure, only your family and friends will buy your produce, so you have to make sure that the little you sell is of good quality. To do this you'll need money to improve your facilities, which you can only earn by winning loyal clients.
Besides upgrading your facilities, you'll also need to invest in your animals and stables, where you can store all the livestock to produce meat and other goods. If you invest your money well and reap your harvest before it goes bad, with time you'll create a prosperous farm that makes you rich.
You'll have to pay attention to how you run your business, if you don't want to end up losing clients and seeing everything be lost. In short, Big Farm offers a fun way to play businessman and farmer, even if it is just figuratively.