It may sound a bit ridiculous, but nobody will lend money to someone who always pays in cash! You have to borrow money or make expenditures and paid again to borrow large sums as time progresses. Start with local merchants in your immediate area, those who already know. Even if you dont need it now, ask if you can set up a charge account with them. In most cases, be glad to oblige you, I know you're local, and regularly sponsor. to acquire credit, charge a few items each week, and pay their accounts immediately when they occur. In this way, you build a good credit record with these merchants in a short time.
Get your bank on the Law of Going to the bank where you keep your checking account, and borrow a nominal sum (say $ 500), which is unlikely to refuse you. Do this even if you do not need the money, because you do not need the payment record on their books. Repay the loan on a regular basis when due. Do not accelerate, and pay it all again next month. Curiously, the banks do not, because that indicates a "feast or famine" situation, rather than a steady payer. The cost of interest on this loan even if you do not need the money will be well worth paying to build their credit history. In addition, you can minimize this interest cost by depositing the money you have borrowed (assuming you do not need immediately) in a savings account and interest charges, which cover much of the cost of the interest is paying.