Attending MITES definitely will help your application to MIT, so that’s a big advantage for you.
This summer you should spend the time looking at the websites of all the schools suggested, to get a first deep dive into what each one offers. After awhile, things start to look the same! But there are differences (research opportunities for undergrad, club culture, studying abroad, etc.). You won’t have time in senior year so this summer is the best time to do this.
Then, whittle down your list. When you are at MIT, take the time while in Boston to do tours of other schools in the area. Super important to get a sense of a campus. Now, summer is not a great time to tour since official class is out, but it’s better than nothing. You want to get a sense of how getting around Boston can be - remembering that there are four seasons and if you’ve never experienced snow, it’s a thing. Also, if you can, try to visit other campuses while you are on the east coast. Perhaps others in your program would be willing to travel with you to make it affordable.
Also tour any schools that are near where you live now. This will help with whittling down your college list as you start to figure out what you like or don’t like about campuses. (Large campuses mean more time just getting to and from class - throw in weather, and it’s a different experience than what you have in high school.)
Your mom’s YOLO list of reach schools is just a list of names - so many parents want the name recognition for the kid but what fits their kid would be much better in the long run.
Really look at reach schools to see what interests you and what doesn’t. CalTech is less of a fit for you than Stanford or MIT would be - for tech reaches focus on the latter two.
Also, think about what you really want from the college experience. Sometimes, a slightly less rigorous school, that allows for research and club time outside of class is a better choice.
A lot of students have studied way more math than you to get into STEMMY schools. So even though there is no limit to what you can learn math-wise in the future, you want to be in a cohort of students that you can be challenged by, but not overwhelmed by. This might mean a school that is less reach and more fit. That’s what researching schools is about.
You’re at a phase where it’s exciting to look at all of the possibilities. Eventually, you will start to see what is best fit for you. That’s when the search is harder but more rewarding.
Also, there are so many top schools in California that are great admits, and you won’t have to travel far to get back home should you gain affordable admittance.
TL;DR:
-draft your oversized school list/spreadsheet
-click deep into their websites (a couple a day) to see what they offer in set categories
undergrad research, student support, relevant clubs, studying abroad, etc.
-work with your mom to figure out the cost of attendance (COA) on each school’s calculator
-visit some SoCal schools while the school year is on locally, if possible
-visit schools while at MITES; go with other students to make it cheaper
-test during the summer (scores are helpful to schools that look at them)
Good luck!