The Lost Alpha Princess

As the adopted kid at home, I’m ignored by my parents and verbally abused by my sister. I didn‘t expect I will see a stunning Alpha Billionaire standing in front of my door, with luxury gifts in his hands.
"So ... you’re Mr. Wilson's lost child."
"No … Wait…what? What … what do you mean?” My mind spun.
"I’m your fiancé," he said with an attractive smile.
It has to be a joke.
Expensive gifts, a billionaire father, and a hot fiancé….How am I supposed to process everything？！