Here "Now" is used here to mark a break in the main story line. Here the narrator begins a summary that explains how the generations of Israelites after Joshua sinned and worshiped false gods so that Yahweh punished them, but then he would send judges to rescue them. This summary ends in 2:23.
The events of 1:1-2:5 happened after Joshua died. This is recounting events that happened at the end of the book of Joshua. (See: [[rc://en/ta/man/translate/writing_background]])