1) Earn up to 200 gold tickets: Up, down, left, right, circle, right, left, down up, circle : type this combination 4 times, you will hear a sound then push the start button. If you do not here the sound, you must have type the code incorrectly.
2) No money taken from bank: left, down, x, circle: type this combination 8 times and you should hear the familiar sound. Push the start button to access the cheat.
3) Open your park with full collection of rides, shops, etc: up, down, up, down, left, up, down, up, down, right: type this combination 8 times and access the code with the start button in the end.
P.S. This cheats only work for the PS1 version of Sims Theme Park.