For 20 years, my biological father ignored me and told me whether I should break up with him. What should I do? ...

Regarding the relationship between you, the law can't cut off the blood relationship, and no one can cut it off. Therefore, even if a lawsuit is filed, the court will not accept it.

Your father has the right to sue your grandparents for alimony. Your father is lazy to support the performance of his obligations, and the person who should pay compensation will perform his obligations in his name. Based on compensation, you can bring a lawsuit to the court because you are not the subject of rights.

However, you can get the alimony required by your father in the future because of his legal obligations, but because you are 17 years old and have no capacity for civil conduct, you can't participate in the litigation, so you can exercise your guardian's litigation rights.