Because there is no requirement for number of guests or park rating, don't be afraid to cut corners and get every dollar out of your guests. Cut back on handymen and charge guests to use facilities. Keep in mind that while you don't need guests to succeed, you still want their money. As long as your park is kept running with a few extra rides, you should see no problem in guest generation. Your first goal should be to get a working roller coaster with an excitement of at least 6.00. An early Motion Simulator will make some good passive cash, and from there you should focus all research on coasters. Start with a small, cheap coaster. The hairpin coasters such as Wild Mouse and Wild Mine have great stats and can be built for less than $5,000.
The large boulders in Razor Rocks may seem like obstacles, but you can utilize them to get extra excitement out of your coasters. The key is building inside the mountains, with lots of tunnels and even entire rides completely underground. This boosts excitement substantially, so a relatively simple ride can easily get over 6 excitement.
Once you have a good roller coaster, you should be generating plenty of money to fund future construction. Charge as much as you possibly can for your coasters--if the excitement over 6, you can start out charging $8 or more for admission. If it is well-designed, people will happily pay this. As months pass you will be getting access to some of the best coaster types in the game, including the coveted Giga Coaster. These rides should get well over 6 excitement without even trying, as long as the Intensity is kept in check. Your only real limitation in this park is money, so focus on making as much as possible and using that directly to build more coasters. Don't overdraw on your loans--only take as much money as you need and pay them back once you start generating profit. You should eventually hit a point after building 3 or 4 coasters that money will no longer be an issue. From here it is only a matter of time to complete your park and get some quality coaster building practice in.