There are usually multiple strategies to successfully completing a scenario; these can be discussed on the scenario's discussion page or written down in an existing or additional section of this article.
This objective can be taken at any pace, so do what best fits you. Start off by expanding the pathway to allow more rides to be built. Start off with a nice mid-range coaster and some thrill and gentle rides. By expanding the park with more rides, it will get harder to keep an eye on everything (especially if you expand rapidly). You can hire more than 200 employees, so hire what you feel is right for the park. Assigning patrol areas is recommended, especially with mechanics near your more dangerous rides (if any).
An OpenRCT2-made Icicle Worlds park with well over 4,700 guests, made by zachl1226.
Since no thrill rides are researched until near the end of year two (besides Twist , which you start with), building several roller coasters with medium-high intensity is recommended. These will hold you over until the Swinging Inverter Ship and Motion Simulator are invented in Year 3 or 4.
As you can see, you don't have to finish the park as fast as you can, as there is no time limit. This great park has turned to a Medieval Theme. Scenario finished by RollercoastertycoonX.
Having plenty of benches and stalls will keep the guests happy, but watch out for areas of your park becoming too crowded, as it will hurt your rating. If you have completed Arid Heights and/or Crazy Craters previously, you shouldn't have much trouble.
Also, don't forget to have fun with the scenarios without funds. Don't hurry and you could make a great theme park, since you have unlimited time. Just keep the park rating over 700!