I was told that :
пошёл
- went somewhere and (usually) haven’t come back yet (and told that I can use ушёл here too) if you state it as a fact or as a part of a story with other actions following one another.
ходил
- a fact and can mean a one time occurence in the past
сходил
- not as significant to mention / may mean for a short amount of time.
Are the descriptions / details regarding these verbs of motion accurate observations and why would someone ever choose сходил instead of ходил? :
Она́ ходи́ла
приме́рно на со́рок пять мину́т. (ходи́ла fact - there and back)
Она́ пошла́
приме́рно на со́рок пять мину́т. (пошла́ left and no one knows where she's at or part of a story and not a fact)
Она́ сходи́ла
приме́рно на со́рок пять мину́т. (сходи́ла there and back or insignificant)
Я пошёл сходи́л
на рабо́ту и пото́м, я пошёл в университе́т. (сходи́л
because the action was completed (пошёл
means that you just started off toward somewhere)