Just have rides in your park. No Shops No Staff.
You don't need janitors if there are no shops and no vendor without shops. I need at least 600 people until it becomes beneficial.
. Just add a few of the cheapest flat rides and start making money with those. Try to make, let's say, $20,000 before shops comes into the picture. Then get 1 food/drink shops. Don't forget to add 1 toilet. That they need. You won't need a mechanic's salary if you rename a ride FRONTIER. Those little things helped me so so much in scenarios. You can always fast forward the game to make more money on the rides so you can get on with the rest of it.
Hope that helps!
Heather