A travel is a quite generic term representing a shift from point A to point B
And you can also travel in time
A trip is usually a short travel, frequently related to a specific purpose, like business (business trip) or tourism (city trip)
In a trip, you come back to your original point.
A journey is usually for expressing the fact that it is a travel on a long distance and/or for a long duration, and/or that you need specific preparation
E.g.: a journey to the south pole
Please also note that you journey, you travel but you go on a trip
(you can trip but it means something else)