How much of a "hook" is legacy at a college?

This is not a troll post, so please bare with me. I'm currently a high schooler about to start my sophomore year at a super competitive high school. I had a really weak freshman year (3.92 GPA, no clubs/extracurriculars besides piano), but I'm planning to bounce back next year. I have multiple AP classes, editor role in the student newspaper, and a club officer/treasurer gig lined up. I've also started preparations for the SAT/ACT exam and found a college counselor to help guide me through the process.

One of the main things I'm concerned about is the lack of a hook. From the start, I've always been an "average" student, with no particular talent in sports, math, computer science, arts, etc. I come from a family of engineers and I'm expected to perform well in math, but I just got by with an A this year only due to hard work and excessive studying. I thought about developing a spike and realized that my skills lie in the liberal arts (literature, history, etc.), much to my dismay, but I actually see this as an oppurtunity. My current plan is to brand myself as a liberal arts student, which will definitely differentiate myself from the rest of my STEM-focused high school.

This brings me to my next point. I am fortunate to have a father who attended the Chicago Booth School (class of 96 or 97, can't remember clearly) and made some (meager) donations a couple of years ago. My father told me that this particular point would add some extra credit to my application, but not much. Multiple posts on College Confidential, however, suggest that having legacy is a super big deal. My question to all of you is, does having legacy at the graduate school hold any weight for the undergrad college at the institution?

Forgive me for rambling, but I am seriously concerned about my academic future. Those who see me as overly pedantic are entitled to their own opinion, but I seriously don't want to end up here in 5 years with that same "HELP 3.0 AT NON-TARGET NO INTERNSHIP WHAT TO DO???" post that only receives sanguine responses. I've been obsessed with watching college decision videos on YouTube and I see countless great students rejected from all the Ivies and only accepted to mediocre schools like Boston University and Villanova, but other students with mediocre tests scores and grades studying at Princeton and Northwestern because they made themselves look unique.

Finance is an incredibly meritocratic industry, and I am curious how all of you made it in. Please share tips on how to brand myself as someone different compared to the rest of the students at my high school so I can get into a decent school.