Depending on what area you live in and what grows well there, you can use many plants for landscaping. They are pretty and most people walking by will have no idea you are actually growing food. I saw a great site with some ideas for this. . . I'll track it down for you.
This isn't specific to just carrots, but includes all root crops in general: "Proper soil preparation is very important in achieving success with the root crops. They grow best in a deep, loose soil that retains moisture yet is well-drained. Root crops do not grow well in very acid soils. Always remember to take a soil sample for pH and nutrient analysis and apply fertilizer and/or lime appropriately. Nitrogen recommendations for beets, carrots, parsnips, and rutabagas are about ¾ to 1 cup of urea/100 sq. ft. Apply half during seed bed preparation and sidedress the other half in mid-season. For radishes and turnips, nitrogen recommendations are about ½ cup urea/100 sq. ft. to be broadcast and incorporated before planting. P and K application should be applied according to soil test recommendations. The optimum pH range is between 6 and 6.5. Liming will raise the pH of acid soils. You can improve soil conditions by adding well-rotted manure or compost. Do not use fresh manure as it can stimulate branching of the roots, compromising the quality of the crop and may increase weed problems. Deeply till the soil, then smooth the surface in order to prepare a good seedbed. Do not use a weed and feed type fertilizer. They contain weed killers that will kill vegetable plants." More here.
Carrots don't like rocky soil, either. They fork or get all bent out of shape.
Weeds are the enemy. Some folks mulch around their plants. If cost is an issue, use newspaper. And go for vegetables that are good in nutrition & sustenance per acre. I would aim towards most beans (except green beans which are low calorie filler) and squashes. They're good for beginners.
If your soil sucks, consider a raised bed or container plants. This will open up other good veges that you normally wouldn't be able to grow.
You can increase you yield and improve your soil by using raised beds. My land is weird ....depending on where I dig, I dig up different soil..from clay, to sand, to rich dirt which is one of the reasons I have 3 raised beds.