Crete is a big island with lots and lots of hidden places, natural beauties and endless beaches. Not to forget about the history and the archiological sights you may be interseted in.
To be able to see all the things you want to, you must use either a rental car/motorbike or you travel with public transportation, which is in Crete only the public bus.
I tried to make it as easy as possible to find here exactly what you need to travel around Crete without troubles or difficulties.
Travel around Crete by bus
Travel around Crete by car
Travel around Crete by motorbike