1)
Where had Yaravam gone, and to where did they call him?
1.
Radak: When all of Yisrael went to their tents, Yaravam went to his house. The verse does not mention to where they gathered afterwards. Perhaps they returned to Shechem, and this is why he made it his capitol.
2.
Malbim: He had gone to Egypt. Some of his friends called him to return. After he returned, all of Yisrael put their eyes to him to rebel [against Rechav'am] at the proper time, just like he rebelled against Shlomo. Until now, Yisrael wavered. (Now they decided to declare Yaravam king.)
