hey i have rct3 deluxe and when i want to create my own park and on the part where you can expand your land bigger thats not a problem when i put rides on they go on but wont let me put entrance or exit on it, can anyone help me solve this cheers

Please clarify, what exactly happens when you try to place an entrance/exit?
Also, try looking in the ride information window (roller coaster car with an i in a circle next to it)
There should be two buttons in a line of buttons, on with a red building with an arrow pointing away, and another with a green building with an arrow pointing towards.
They should allow you to place the entrance and exit.