甲斐がない/甲斐(も)なく => it's not worth one's efforts to do something N2
甲斐がある => It’s worth one’s efforts to do something N2
に行く/に来る/に帰る => go/arrive/go back (to do something) N5
へ => Go to N, head to N , Often followed by verbs like 行く/いく, 来る/くる, 向かう/むかう… N5
Particles