1) I want to ask about khums whether there’s any rule regarding single daughter or if girl receive any present or gifts , she doesn’t have to pay khums on her gifts or money she received from her relatives?

2) What if her father told her to save your amounts with niyyat for your marriage ie as dowry for which khums is not liable. Later the girl spent the money for her purpose so what should be done?

1) There is no difference between male and female.
If she did not use the gifts during the year, you have to pay the khoms from her money.

2) The dowry is paid by the groom, not the bride, and this is the one in which the khums is not required.
As for the money that a woman saves for the necessities of her marriage, because she must furnish the house, as is the tradition with you, she does not have to pay its khums if she buys the necessities with it. But if she kept it as cash, then its khums must be paid by the end of the year.