You do need some money in the bank in order to buy a home. A friend or relative can lend you the money, (talk to your loan broker about the rules for that- i have a couple i trust and work with) but in my understanding, here is a brief list of what you will need.
If you are a veteran of the US Military and can get a VA loan, you can get a 0 down loan, but you will still need about 3.5% of the selling price for closing costs. If you cannot get a VA loan, you will need at least 3.5% of the selling price of the home to use as a down payment for an FHA loan. If you are buying a $100,000 home, you will need at least $3500. Then, there are closing costs. Those are the cost of the loan, the appraisal, any inspections you have, title insurance, some property tax that you pay early, the first sometimes almost 2 months of payment, for another approximate 3-5%. So on that $100,000 home, you will need another $3000 to $5000, for a total of about $8500 out of your pocket to buy a house at $100,000.
The more money you have to use as a down payment, the better your offer will be regarded by the listing agent. People with 20% down seem more solid and more likely to be able to complete the deal than someone with nothing down, so you want to put yourself in the best possible situation so that when you find the home you love, you will be able to buy it, and not have your offers rejected. There is a lot of competition in the under $800,000 price range, with multiple offers happening all the time. So be ready, get your finances in order, and then you will be successful!