It's a bit harder than that.

You need to know how deep to till (it depends on where you are). You'll need to fertilize the soil, but not too much (again it depends on where you are). The soil mustn't be too wet or too dry. Irrigation can get quite complex. Again it depends on where you are. Rain-fed agriculture doesn't work everywhere, plus it leaves you vulnerable to droughts. Too much rain and you'll have to get rid of the excess water. Any operation at scale will need proper irrigation (this is one of the things the Zimbabweans just couldn't do, in fact - they ripped out the pipes the whites laid to sell for scrap, then they were surprised they couldn't grow much). Then there's pest control. (In Zimbabwe, animal and human pests - you could say even the white farmers failed at this.) Plus, you'll need to deal with weeds and crop diseases. Can you afford Monsanto's seeds and Roundup? That's the easiest way. If you want to go the biological route it's another long list of "it depends on where you are". You'll also need to be careful about not exhausting the soil, if you want to grow something next year as well.

Even if you manage it, OK, then you'll have a bunch of corn. Can you process it? Store it properly? Can you sell it easily? Can you transport it? Again, this is where Zimbabwe failed. Even if you only aim to feed yourself and somehow don't need to pay taxes, you still need money to pay for upkeep of the irrigation systems, to buy fertilizer, etc, etc.