Begin the scenario by researching the Information Kiosk. This will be invaluable to guests, as they often get lost near the back of the park (with the River Rapids). It may be a good idea to research Ride Improvements as well, as you can unlock the Water Splash for the Wooden Roller Coaster fairly early in the scenario. You should also connect a path across the lake from the exit to that ride to the area with the Boat Hire and fill the gap with some rides.
The Water Slide that has already been built may stall out at times, so it is best to leave it always waiting for a full load (uncheck the "Maximum Waiting Time" option in the ride options panel) or alter the ride slightly. It still might get stuck after a couple of breakdowns, preventing the dinghies from reaching back to the station and frustrating guests. If this happens, pause the game, click the close button of the ride twice, and reopen. This way, you only lose the guests on the ride and the ones still queuing will still ride it without any fuss. There is no minor change to the ride to make this preventable.After that, build some gentle rides, mainly the Merry-Go-Round and Haunted House because this scenario is fairly rainy. The lake is a good place to put a roller coaster, and the hills near the Log Flumes are good for building an underground roller coaster. If you choose to extend the path past the River Rapids, there is another good place to put a roller coaster. The park lacks stalls (like most parks with pre-built rides) so make sure to build some. Also make sure to add more benches and trash cans to the paths, as they are seriously lacking. Hire more handymen and mechanics and order the pre-hired handyman to stop mowing lawns. With good skills, you can achieve 1,000 guests before Year 3.