What is the ruling on taking out a loan from a bank to furnish a marriage apartment and cover the costs of a child's birth, and how can one repent from that?

Borrowing from a bank with interest is usury (riba), one of the gravest sins. However, whoever repents, Allah will accept their repentance. Remorse is a sign of sincere repentance, for the Prophet, peace and blessings be upon him, said: "Remorse is repentance." One must seek forgiveness and resolve not to return to it, for usury is not permissible except in cases of necessity, based on the Almighty's saying: "And He has already explained to you what He has forbidden to you, except for that which you are compelled to." and "But whoever is forced, neither desiring [it] nor transgressing [its limit] - then there is no sin upon him." Necessity is that which makes it highly probable that destruction or unbearable hardship will occur, or the inability to achieve the minimum standard of living for the poor.