How can one repent and be delivered from an interest-based loan taken to purchase a shop, and another to purchase an apartment, knowing that the borrower lives in France and has been blessed with a child whom he does not wish to raise on unlawful money?

First, one must offer sincere repentance for taking a loan with interest (riba). After repentance, the principal amount of the debt should be repaid without the usurious interest if possible. It is not permissible to pay the interest if it can be waived. If it cannot be waived, then hasten to repay the debt to reduce the interest, if early repayment waives any portion of it. As for the bakery and the apartment purchased with this money, there is no need to sell them. The prohibition is related to one's conscience and is absolved by repentance. What is earned from them is permissible (halal (definition)).