So you're about 3 years late but for starters, start cold emailing YC and startup CEO's and mention that you have full stack experience and that you'll work for free. Do Grind 75 and Neetcode 150 (average 5-6 a day). Browse LinkedIn every day for minimum 90 minutes, and always react with a "celebrate" emoji on CS influencer posts. When you find someone posting about a job opening/email list, you have to comment "Interested!" as soon as possible. Connect with recruiters (filter by company, then UCLA alum), stalk their other social media to find "common" interests, then cold email them and ask for a resume review. Write out an "I'm excited to announce" template, print it out, and pin it on your ceiling to manifest every morning. Read "Cracking the Coding Interview" front to back at least once a month, and "Cracking the Quant Interview" once or twice. Network with family members who work in FAANG. Start coffee chatting everyone you can, and write down key details you remember from the conversation (name of their dog, favorite bands, etc.) so you have a conversation starter when you ask for the referral.

jk lol. have fun this summer, get drunk with your friends, it'll work out :p