A hook is an institutional reason why a college would want to accept you over other similarly qualified or sometimes somewhat better qualified candidates. Very few people have hooks and if you did you would know it. Some examples of hooks are: recruited athletes, children of huge donors, people who would bring positive press to the school (ex. Malala).
And nobody here will stop you from applying but your GPA/rank do not appear to be in range for BU or UMiami. Below is the class profile per the school websites (if you google “XYZ university class profile” or “XYZ university common data set” and look at section C you can get this information yourself).
https://www.bu.edu/admissions/why-bu/academic-profile/
https://admissions.miami.edu/undergraduate/about/class-profile/index.html