More visitors
When you are in Dinoland, just ignore or delete the message about the cheap gate price to get a lot of visitors.

More money
Start a small park with four puzzle games close together, two rides, one food, one bathroom and a gate price of $0. If you set it up so all four puzzle games are within view of each other, you can do the global price raise/lower for all puzzles while all four are active (making $40,000 at once) The $0 gate price will get the visitors in fast. Set the prizes value to $10 and a maximum win possibility. That makes the visitors happy, stay longer, and play more. If you need to take out a loan, take out the least amount of money. Then later in the game, when you have a little bit more money, take out the $30,000 loan (or the highest one) and pay off the first loan. You will still have enough money to buy rides and attractions without going bankrupt.

World of Wonders park
Collect three Golden Keys.

Space Zone park
Collect five Golden Keys.

Better park operation
Assign staff members to a certain area. This way the park is cleaner, rides are fixed faster, and more people get to see entertainers. Note: Put a staff room in each area.