How can parents build love of the masjid in children?
Bring children regularly, connect the masjid with positive routines, and let them feel welcomed, not managed.

Imam-Reviewed Guidance
فَاسْأَلُوا أَهْلَ الذِّكْرِ إِن كُنتُمْ لَا تَعْلَمُونَAsk the people of knowledge if you do not know. — Surah Al-Anbiya 21:7
Bring children regularly, connect the masjid with positive routines, and let them feel welcomed, not managed.