Can i apply for dole & not tell them i intend to go to college in sept what will happen when they find out?

Yes you can. You are looking for work now and available for work till September. You are not a student until you start your course. You can only get in trouble if you carry on claiming when you start your course. You can't see into the future. You say you intend to go to college, there is no 100% guarantee you will go. You might find a job you like and stay in it or decide that the course is not for you. Dole is paid for what you are doing NOW and not in 6 months time.