This scenario can be easily completed by taking advantage of all 5 marketing options (you can't use half price and free vouchers at the same time). When you start, pause the game and reduce your loan to $5,000. Raise the price of food and drinks around the park by about $0.30 each. Raise the park entrance fee to $50. Any issues with money should be eliminated now, so spend the remaining $5,000 on marketing. Look for areas where there is a lot of litter/vomit and assign handymen to those areas. Place 'No Entry' signs where they are necessary, and hire security guards to prevent vandalism as you progress into later years.
Every time an advertising campaign is finished, re-buy it. Add a couple of the gentle and thrill rides that aren't in the park yet, but make sure to hire more mechanics for these extra rides. A new roller coaster can help attract a large crowd quickly, too. Consider replacing Great American Scream Machine with a smoother clone, like a variant of Twister Roller Coaster, which will increase its excitement while lowering its nausea and intensity. Guests will also consider this a new ride.You can keep it in the same layout and location, though you will have to build it again from scratch, as the pre-built ride cannot be edited. Using this strategy can get you to the objective before the Year 2, and can also be applied to Six Flags Over Texas, though that park will require a few more rides.