How can one attain the parents' pleasure, and does their displeasure lead to God's wrath and prevent one from entering Paradise?

Filial piety is among the most obligatory duties and the best acts of obedience, while disobedience to parents is among the gravest major sins. This is based on the Prophet's (peace be upon him) saying: "The Lord's pleasure is in the parent's pleasure, and the Lord's displeasure is in the parent's displeasure," and his saying: "The parent is the middle gate of Paradise."

Honoring them involves showing humility and speaking gently, avoiding arguments and causing them harm, as Allah Almighty says: "And speak to them a noble word."

You must repent to Allah for having wronged your parents. Repentance involves abandoning the sin, regretting it, and resolving not to return to it, along with apologizing to them and seeking their رضا (رضا).