קרא qar'a "call" either "to call someone (by) some name" or "to call to/on". In Amos, Adonai three times "calls to" agents of destruction at 5:8 and 9:6 (in the hymn fragments) in much the same words he calls to the "waters of the sea" to pour them over the land in a new flood (presumably like Noah's) and at 7:4 in the visions he calls for "judgment by fire". Others "call" in 5:16 in the context of suffering the punishment.
The niphal (passive) is found at 9:12.
The hiphil means "proclaim, announce" in Amos it is found at 4:5.
In Amos 4:12 the infinitive comes from a different root meaning "meet,
encounter". In Amos 4:12 the infinitive is used in a construction usually translated
prepare to meet your God!" (The infinitive usually means either
"meet" e.g. Gen 46:29;
Ex 4:27; 18:7; 19:17
or "draw up battle lines" e.g. 1 Sam 4:1, 2; 17:2,
21.)