First of all, consider demolishing Frightmare, as its nausea rating is very high. You can use the money from doing so to replace the coaster with several other coasters. If you keep it, remove the final sequence of inline twists, add a section of helixes and brakes before the station to prevent crashes, and assign a mechanic to it exclusively. Demolish or block off unused paths, as well, to keep guests from getting lost early on.
Build a few smaller coasters like the Wooden Crazy Rodent Roller Coaster and launched coasters to start generating revenue. Add more roller coasters and smaller rides as you can, keeping in mind that quantity, quality, and variety matter equally. As it is easier to attract guests in the first year, you may wish to pull out your maximum loan at the outset to give your park a jump-start with some exciting roller coasters regardless of what you do with Frightmare.
Your guests are hard to attract and please this time around, so you will need to be quick to address every problem your guests mention. Do not be afraid to add shops and stalls at every corner if your rides are sufficiently profitable. Keeping your park well staffed will help you keep your paths clean, rides in working order, and park rating high. Nevertheless, you will need to advertise, so be prepared to run all available campaigns constantly to bring guests in.
If you do not have at least 1000 guests by the end of the first year, consider restarting the scenario. In your second and third years, consider making some of your rides permanently free; this is most affordably done with the Crooked House, but not unfeasible with other rides including small coasters and transport rides if you have enough money from big ticket rides to cover the cost. If you stop expanding and advertising, you will start losing guests at an alarming rate, so beware.