Your first stop should be with your lender to determine your borrowing power and whether or not you will need a co-signor, the lender is the best source for this information. This will also give you the opportunity to discuss getting a construction loan to build the house and how to best build your credit to qualify on your own. Your second stop should be with a Realtor who knows the area you are planning to buy within. The owner may want $9,000 an acre but the land may only be worth $5,000 per acre and the last thing you want to do is overpay. Also the Realtor can help you with the proper questions to ask the seller (like what the zoning is, road frontage vs recorded easements, etc)
All this aside I don't recommend you go forward with the purchase unless you are 100% positive you will build the house and live in it for at least 10 years after it is completed. Younger people tend to live lifestyles that allow them to move easily more often, but building a house is a commitment to put down some serious roots, especially if it is in a rural area. Rural homes are often harder to sell, so if you may have an idea to move elsewhere for a better job in a few years, or there is potential your present employer is going to transfer you, you might want to hold off on this idea for 10 years.