The center of the park doesn't have much space to build, but there is enough space on the hills around the park. Start by expanding in one direction, and start building a circle. When you reach the area above the entrance, consider building a path from the top of the hill to the initial underground path at the entrance. That way, guests are less likely to get lost.
To attract 1,300 guests, you will need a few roller coasters. There are a few roller coasters available for research that don't need much space, like the Steel Wild Mouse Roller Coaster. You can also build coasters underground. This is especially recommended for the Mine Train Roller Coaster, as it will get a significant boost to excitement rating if it features some tunnels.
Getting money should not be an issue. Set a reasonable entry fee (~30$ in the beginning). Zygorators 1 & 2 will give you a nice boost, as you don't need to build a roller coaster as soon as you start. Instead, build a gentle ride, one or two thrill rides, and some stalls and start advertising for your park. Once the cash comes flowing in, build roller coasters and add in some thrill and gentle rides when they are researched. You should plan ahead and build compact coasters, as you will probably need at least seven in the end. If you are a few guests short in September, start another advertising campaign.
Note: You might want to connect paths from the entrance to the back, as guests tend to get lost easily. You may also want the Information Kiosk which give Maps to guests. You will also need to research the Drinks Stall, as it is not available to build at the start of the scenario.