This scenario is one of the hardest Expert scenarios in RCT2. The height restriction and ban on advertisements at this park will push you to your limit. Experience with Amity Airfield and Fungus Woods, as well as Harmonic Hills and Pickle Park from the RCT1 expansion Added Attractions, will help.
Start by building stalls and all of the flat gentle and thrill rides you have available. Avoid building tracked rides on what little flat land you have, and instead build as many flat rides there as you can. Once you have done that, close the wooden coaster and edit it to include a photo section; this will not boost your income significantly, but it will help alleviate running costs. You may close the chairlift temporarily or demolish it, but you should eventually add a path to the top if you wish to build up there.
You should now be ready to increase your park entrance fee to $40. Keep your food and drink prices at or near the default so that you can hopefully attain the Best Value Park Award. Now, build a roller coaster smartly, using the hills to gain height; the wooden coaster already in the park is a good example of what you should aim to build. Once the new coaster is open, raise your entrance fee to $45 and leave it at that for the rest of the scenario.
To reach your goal of 2500 guests, you will need to continually build more rides, keep your park rating high, and strive for positive awards. Go for a mix of quality and quantity; while building large and exciting rides will certainly attract guests, building smaller rides will be better for your bank account in the short term and help you fill your park. You have plenty of space available, so do not be afraid to expand when you can.