i cant remember much bout english coz i already finished HSC english, but from what i recall is that there are 2 types of journeys that can be embarked upon, one is the author use of imagination to present the text such as poems (which may be a personal recount of what happened in the past) and second how the text stimulates your imagination whether it is through colours, poetic techniques, symbolism etc. i also have some notes which may be of help
Here are some notes from 'topnotes'
The journey is fuelled by the human capacity to imagine
Imaginative journeys open up amazing possibilities - limited only by our capacoty to imagine
An imaginative journey can be shaped by an individual it can be shared with others so that they too can appreciate the experiences
They offer a reprieve from the realities of life
They may be pleasant interludes of longings achieved or the exploration of new worlds that are not like that which we live in. Thus imaginative journeys can explore possibilities and potential