The Upside of Falling by Alex Light (Wattpad)

It's been years since seventeen-year-old Becca Hart believed in true love. But when her former best friend learns her for not having a boyfriend, Becca impulsively pretends she's been secretly seeing someone. Acting like the perfect romance tutor, Becca uses her smarts to prove to herself and others that she's the perfect girlfriend. She's written by Alex Light. This is a Wattpad book.