In the beginning of this scenario, you have two profitable roller coasters and a lot of open areas to build on. Set your research funding to maximum and direct your priorities to Shops and Stalls and Thrill Rides, as you have very few of each to build from the start.
Consider moving the Ferris Wheel to a new spot in the park--preferably where most tracked and other flat rides do not fit (near Defibrillator would work). Space management is key in this objective; thankfully, Grapevine takes up little room for its length and can be easily surrounded by flat rides. Keep an eye on Grapevine, though, as it cannot safely stop during a Station Brakes Failure. To counter this, station a mechanic directly at the exit or remove the second train and replace the remaining train with an 8-car standard model. It's also a good idea to edit Grapevine to put brakes before the final set of helixes, then add chain lift on the hill up to the station. Also put in an On-ride Photo Section somewhere to boost your profits from Grapevine even further. Once your park starts picking up steam, you should be able to build a new roller coaster such as a Steel Wild Mouse Roller Coaster.
By the end of Year 1, you should have anywhere from 600 to 1,100 guests in your park. At this point, you can expand your research priorities to Roller Coasters and Gentle Rides. Slowly expand your park with a variety of flat rides and small to medium-sized roller coasters throughout Year 2.
By the end of Year 2, you should have anywhere from 1,100 to 1,600 guests. You may start to notice guests complaining about overcrowding, but you should be making a lot of money. Focus now on improving and maintaining your park to earn awards. Try for as many as you can, including the "Most Beautiful Park Award" and the "Tidiest Park Award", but strive chiefly for the "Safest Park Award" and "Best Value Award". Towards the end of Year 3, scour your park for and remedy any vandalism, vomit, littering, and overcrowding to keep your park rating from dropping too low before the end of the scenario.
To put it shortly: focus on rapid expansion and ride profit during Year 1, slow expansion during Year 2, and customer satisfaction during Year 3.