Journey (noun) means traveling from one place to another, e.g. from A to B, usually taking a rather long time; also called a trip.
For example: I walked from Taipei to Taichung (two cities in Taiwan). My journey (trip/excursion) took three days.
Tour (noun) means:
1. traveling around from place to place,
2. a long journey including the visiting of a number of places in sequence, especially with an organized group led by a guide, e.g., from A to B to C to D and back to A.
3. a brief trip through a place, as a building or a site, in order to view or inspect it: e.g., The visiting prime minister was given a tour of the chemical plant.
4. a journey from town to town to fulfill engagements, as by a theatrical company or an entertainer: to go on tour, e.g. The band was so popular they decided to tour (travel to and perform in) 15 cities in Taiwan.
5. a period of duty at one place or in one job, e.g. The soldiers had a one year tour of duty in another country.
If I travelled from Canada to Taiwan, that journey would take 12 hours by plane.
After arriving in Taiwan, I would like to take a tour that went to all the important tourist sites, and also take a tour through Yushan National Park.