to enter, to go in / to fit, to be contained / to emerge, to arise / to start, to begin

entrance, entry, place of entering / beginning, start

to get down to brass tacks, get down to business, cut to the chase

to go to someone's head

(idiomatic) to turn to the crux or climax; to get to the heart; to cut to the chase

(intransitive, idiomatic) to take up office

(theater) to go on stage / (figurative, by extension) to begin to have a presence or effect; to enter the picture

to go into action

to go to war

come into play