Trip can be used to refer to any time you leave your home in general. A tour implies that you are going to with the sole intent of visiting places of interest and you may have a guide to help you. A voyage is travelling by means of a ship/boat. A journey implies a trip where you travel long distances over ground and often has the implied meaning of requiring a lot of effort. You wouldn't usually call flying somewhere and staying in a hotel a "journey," but you might call backpacking cross country and climbing a mountain a journey. People also use the word journey to refer to something that was a long and interesting experience, whether or not it was an actual journey in the literal sense of travelling.