Here is a common dua that can be recited when leaving home:
بِسْمِ اللَّهِ، تَوَكَّلْتُ عَلَى اللَّهِ وَلاَ حَوْلَ وَلاَ قُوَّةَ إِلاَّ بِاللَّهِ
Bismillah, tawakkaltu 'ala Allah, wa la hawla wa la quwwata illa billah.
Translation: "In the name of Allah, I place my trust in Allah, and there is no power or strength except with Allah."
This dua is a reminder that we should always rely on Allah and seek His protection when leaving our homes. It expresses our trust and dependence on Him in all matters.
Reciting this dua before leaving home is a Sunnah (recommended) practice in Islam. It serves as a means of seeking Allah's blessings, protection, and guidance throughout our journey. It helps to instill a sense of mindfulness and reliance on Allah for our safety and well-being.