Under average GPA: Chance at UCs + other reaches?

Hello, I’m a senior applying to probably too many reach colleges, and I want to major in computer science. I’m wondering just how much of a chance I actually have with these colleges given how competitive admissions have gotten. Realistically, I’m expecting many of these schools to be hard to get into, and I’m mostly fine with transferring from a community college into a UC if I don’t get into any of these schools (btw I live in California).

NOTE: For my UCs, I plan to either major in Computer Science through Letters and Science or go into Civil Engineering and change majors in same Engineering department). Anywhere else and I apply for Computer Science.

Here are my colleges (some potential targets but mostly reaches or super reaches):
UC Riverside
UC Santa Cruz
UC Davis
UC Irvine
UC San Diego
UC Santa Barbara
UC Berkeley
UCLA
CSU San Luis Obispo
USC
Harvey Mudd
Brown
Cornell
UPenn

GPA:
Unweighted: 3.6250 (out of 4)
Weighted: 3.9750 (out of 5)
UC: 3.89
No class rank
Upwards trend

SAT:
Total: 1500
Math: 790
Reading and Writing: 710

SAT Subject Tests:
Math 2: 800
Chemistry: 730
US History: 700

AP Exams:
World History: 3
Music Theory: 5
US History: 4
English Language and Composition: 3
Computer Science A: 4
Calculus BC: 5

Activities/Extracurriculars:
Composing and publishing own music for last 2 years (#1 passion)
Playing piano for last 13 years
Playing clarinet for last 8 years, bass clarinet starting from this year for wind ensemble
Learning 3D modelling and design on my own. Using Unity to learn terrain generation and spending time to learn about how data is stored, how computer components work, etc. (#2 passion)
Various Engineering clubs like Robotics that I feel don’t add a whole lot of value because although I enjoy them, they are somewhat casual
Parkour (fun side activity that encourages me to spend more time outside than just play games most of the time)

Awards:
Outstanding Musician Award (school)
Certificate of Merit (local)
Best of Class at regional CodeDay event (regional)
AP Scholar with Distinction (national? idk)

Essays: Trying to make them as good as possible. Writing about my love for music and how that has allowed me to become more confident and develop a love for learning in general.

Letters of Rec: Asking from people that know me well: my English teacher and my Music teacher. I trust that they will write me a good letter.

Additional Notes:
I am quite socially anxious and introverted, and overall, my anxiety has led to lower grades than I had hoped. In 9th and 10th grade, I was so insecure that I was afraid to try my best because then I would see myself as an emotionless robot (thus I began with a 3.66 weighted GPA). It wasn’t until 11th grade that I had begun to work as hard as I could because I wanted to learn more (both about myself and the information from my classes) rather than BS through my classes (ended with a 4.2857 weighted GPA). I also have a lack of leadership positions because I was too afraid about if I could handle it and kept making excuses to myself even though I really wanted those roles (like being an officer of a club, or a woodwind captain of my band). However, I’ve decided to try to change that this year by beginning to apply for roles like being a peer tutor and hopefully being a conductor for my wind ensemble in 2nd semester (or even perform one of my compositions).

Tbh, I would love going to Harvey Mudd (or many of the colleges on this list), but I’m aware that my GPA is quite below the average for most of these schools. What are my chances (especially for UCs and other schools in California, because I’m not expecting a whole lot from Ivy Leagues)?

Btw, here’s my senior schedule:

Wind Ensemble, Digital Art, Intro to Engineering/Design, AP Literature and Composition, AP Chemistry, AP Statistics, Civics/Economics

I also forgot to put marching band for four years as an activity but honestly it’s not a very influential activity compared to the other ones

My humble opinion is that I think you will likely get into all the UC’s other than UCB and UCLA (possible but unlikely) plus UCSD and UCD being a likely but not for sure by any means.
Cal Poly might be tough due to your major. Unsure about USC as I know that one keeps getting tougher to get into. No on Harvey Mudd, Brown, Cornell and Penn.
But, you never know and I think it is worth trying.
Good luck!

UC’s are very GPA focused so a UC GPA below 4.0 is going to make CS difficult especially for the majority of the UC’s but especially for UCSD/UCLA/UCB and Cal Poly SLO. You are a very capable student based on your test scores so if you have a compelling reason for your lower than average grades early in HS, it can be addressed in your personal insight essays.

USC tends to be more test focused, so your SAT score could help your chances along with some great essays and LOR’s. Your musical EC’s can set you apart from many of the STEM applicants so it can help your chances.

Just citing some UC statistical data which is not major specific so for CS expect lower admit rates and higher GPA/test scores required.

Freshman admit rates for UC GPA of 3.80-4.19 (capped weighted)

UCB: 12.6%
UCLA: 11.7%
UCSD: 38.7%
UCSB: 53.6%
UCD: 56.5%
UCI: 52.1%
UCSC: 75.7%
UCR: 90.1%
UCM: 96.1%

2018 UC capped weighted GPA averages:
UCB: 4.23
UCLA: 4.23
UCSD: 4.16
UCSB: 4.13
UCI: 4.13
UCD: 4.11
UCSC: 3.96
UCR: 3.81
UCM: 3.71

2018 Data:
25th - 75th percentiles for SAT:

UCB: 1360-1540

UCLA: 1340-1540
UCSD: 1300-1520
UCSB: 1270-1500
UCD: 1220-1480
UCI: 1230-1490
UCSC: 1210-1450
UCR: 1130-1380
UCM: 1020-1280

I see no safety schools so you might want to add Cal Poly Pomona or SDSU. Any Engineering at the top UC’s will still be competitive so applying to CE and then trying to switch may not work out.

UCR/UCSC: Match
UCD/UCI and UCSB: High Match/Low Reach
UCSD: Low Reach
UCLA/UCB/SLO/USC: Reach

Best of luck.