Sheesh

learn to code if you want to get ahead.....this other shit can wait till college. 

1) Idk anything about this so can't comment

2) I mean I guess connecting with current students from your HS is fine, but I wouldn't contact anybody in IB until you actually start college/

3) Nobody gives a shit if you have FINRA SIE. Actually, you'd look a bit odd if you did. People would think you're a total hardo.

4) Lol assuming you don't actually have ANY finance background, like most high schoolers, you should probably study some accounting first. Just learn about the 3 statements and how they all think together. You should do that before reading R&B. 

5) While I think you should just relax your last summer of high school, it would actually put you in a really good position to have any finance related internship this summer. I wouldn't say its *impossible* to get an internship at a local investment bank. Just be open about the fact you don't have financial skills. Many, many IB internships pre the one that matters won't have you touch a live model with any significance. Any place would love a kid proofreading pitch decks for free. 

6) For now, just learning basic functions and formatting skills is fine. It's better to learn more advanced stuff when you actually understand what you'll be using it for. A certification would be good for you educationally. I kinda wish I took my high schools MS Office course. I laughed it off at the time, but it would have helped, especially for PPT. You can learn PPT more effectively rn than excel. 

7) Bloomberg Cert: this is actually a decent tool to learn early on. If your school pays, go for it, but learn basic accounting first. The 3 statements are the backbone of all things corporate finance. 

The best thing you can do is to take a step back and look at the bigger picture. One very important skill you need in college is knowing how to prioritize which includes knowing when it's too early for somethings and that other things are totally unnecessary. The period after deciding on a college and waiting for it to start is the most relaxed I can remember myself being since school became important. You will not have a period of 6-7 months where absolutely fuck all matters again for a very, very long time. 

Take an accounting course before reading Rosenbaum as it is pretty inaccessible without baseline info. You could take a summer accounting course before school starts, or just take it your first year. 

Following

Are you fully committed as in you sent an enrollment deposit and everything?

If you sent some application into the Ivies, why not wait to see if you got into any of those first before 100% committing to this? Going to one of those would set you up better. Based on how prepared you are, I think you'd have a decent shot at going straight to the buy-side instead from an Ivy. Keep that attitude up.

Echo learn to code but see if you can get an internship at a local startup. Even if it’s just bitch work, you’ll learn how companies are built, ez professional references, and you’ll be able to interview effectively for the finance clubs in NYU.

Most of the things you need to know/do have been covered already by other comments but I'll add something else.  

Not sure if you want to exit into hedge fund after IB or you are just planning for IB for now and plan to decide later.  Whatever the case, you should start now to build your "investment acumen."   Investment acumen isn't just knowing how to build models but also knowing how to think a bit differently and being able to comprehend your sector well.  So when you do have free time that you otherwise wouldn't have used wisely, read up on sector/industry reports, presentations, earnings call transcripts, etc. 

Also just want to add that don't pigeon hole yourself to the sector you started researching now (for example if you began researching tech industry now don't condition yourself to only analyze tech stocks as you go on in your investment journey).  
 

The reason I'm suggesting this is because many grads go into IB thinking they will become a top investment analyst on the job but this isn't neccessarily true. Try to "develop" a passion for the markets but if you introspect yourself and find out you're not a huge fan of doing this type of work then that's fine!  

Now I want to be clear that do not go extreme on this as even hedge funds (tradtionally seen as one of the most meritocratic places in "high finance") want an a sharp and chill analyst.  People suggest you to get hobbies outside of finance not just for your mental health but also cuz funds would rather hire people they would like to work with and not just a robot.  

I would take this time to do something actually interesting. You want to do all of the same shit everyone else does to be a monkey that blends into the crowd? Use this opportunity to take on an interesting project, dive deep into an interest, if you don’t have an interest consume as much knowledge and talk to as many people as you can until you find one and go all in. If you can show you are an actually interesting person it will put you ahead when everyone else inevitably checks the same boxes on the checklist that you will end up checking off during college/interview prep.