Banks will usually lend in the range of 1 point to 2.5 points over prime depending on bank, income of the business being purchased and Buyer's experience and credit history. The Broker usually does it for you. Instead of a bank loaning you the money, the Seller does. You give the Seller a Mortgage and a Note to secure the loan. Usually it is on the property being sold.
Payments are usually monthly, sometimes annually.
The Note will contain other standard clauses, as well. Almost nobody builds campgrounds, anymore in this part of the country. It probably costs at least twice as much to build a new campground as buying an existing one which would have an immediate Cash Flow versus waiting 3 - 5 years just to break even. If you don't have enough money to purchase an existing campground, the odds are very strong that you cannot afford to build one. Each campground is different.