trek vs journeying

trek and journeying both are nouns.

Word	Noun	Adjective	Verb	Adverb
trek	Yes	No	Yes	No
journeying	Yes	No	No	No

As nouns, journeying is a hypernym of trek; that is, journeying is a word with a broader meaning than trek:

trek: a journey by ox wagon (especially an organized migration by a group of settlers)
journeying: the act of traveling from one place to another

Other hypernyms of trek include journey.

trek (noun)	journeying (noun)
any long and difficult trip	the act of traveling from one place to another
a journey by ox wagon (especially an organized migration by a group of settlers)

trek (verb)	journeying (verb)
make a long and difficult journey
journey on foot, especially in the mountains