the first part of the month

I go to my hometown.

私は故郷へ行きます

I go to my hometown early in the month.

私は初旬に故郷へ行きます

I go to my hometown in the first part of next month.

私は来月初旬に故郷へ行きます

I go to my hometown by train in the first part of next month.

私は来月初旬に列車で故郷へ行きます

I go to my hometown by train with my younger brother in the first part of next month.

私は来月初旬に弟と列車で故郷へ行きます