I'm a market farmer AKA truck farmer. We grow veggies on about 2 acres. We crop very intensively and with very little unused space in the field. It's a ton of work and doesn't pay real well. But, for us it beats working for someone else and we get to eat really good food.
If you want to make money on a few acres, be prepared for a LOT of work. Like others have suggested, you need to figure out what there is a demand for in your area and then figure out how much time and equipment you will need to grow it at a price that's competitive. In our area there is no shortage of Amish growers as well as retirees who underprice their products at the farmer's market. It's pretty tough to compete with those guys because they don't need to make enough profit to actually operate a business.
You could specialize in a few crops which would allow you to tool up a little better for each crop. Potatoes for example. You can grow a lot of taters on an acre or two. A potato planter and a potato digger can be had pretty cheaply. A basic toolbar with a setup for trenching and also for hilling and a small PTO or 12V sprayer would round out the set. You could do something similar with corn, carrots, squash, pumpkins, etc.
Of course actually growing the crop may prove to be the easy part. If you actually want to make money on that amount of leave you'll need to grow a high value crop instead of hay or soybeans or something. As such you'll end up with a product that requires some equipment and labor for harvest and also post harvest. Coolbots have really brought down the start up price for growing veggies, but you still have up be able to harvest, wash, cool, package, store, and deliver your crop. All of those steps require tools, time, and space. And, of course, that's assuming you have a buyer...