Focus on buying more rooms
One of the most important things early on in the game is to focus on unlocking the double room, and buying a second one. In order to do that you will first need to buy a battery for the generator in order to produce more energy and power to the hotel. That costs 2500 dollars - so save for that. Once you built the battery, you should focus on saving another 3000 dollars to buy the second double room, because that's when you will start making money. The more rooms you have the more customers you will be able to have and that's how you can start making more money. So I suggest that you try your best to unlock more rooms and upgrade them, because that will make people pay more for their stay.