Data Brokers are one of the biggest threats to your privacy. Until there are better privacy laws in the US (and I'm not holding my breath), the best you can do is find them and request an opt-out. @yaelwrites put together an excellent repo of the worst offenders. Working your way through this list reduces your attack surface significantly: https://github.com/yaelwrites/Big-Ass-Data-Broker-Opt-Out-List
There is also a tool called PrivacyBot that is able to mass-mail data brokers with CCPA opt-out requests. It's out of date and broken, but there is still a CSV file in their repo that you can import into a mail-merge program to send your own CCPA requests: https://github.com/privacybot-berkeley/privacybot/blob/master/app/services_list_06May2021.csv
It's messy, and you'll have to verify with a lot of different brokers after mailing them, but it seems quite effective.
A quick note on CCPA requests: They only apply to California residents, but don't let that stop you. Most businesses will comply regardless. If they complain, just say that you live in California but don't have an address there. That is enough to get them moving forward.
Finally, if you want some extra help, there are a number of paid services that will reach out to brokers on your behalf.
The one I *lightly* recommend, and use myself, is DeleteMe, which has done an acceptable job for some of my friends who did nothing manually first, and found a handful of things that I missed.
Here's an affiliate link that gives you 20% off: https://joindeleteme.com/refer?coupon=RFR-186613-FAYDHF (full disclosure: they'll give me $50 if you subscribe using this link).
@Alex
This is what we use, and they also accept requests for ones that their regular searches miss. Their response is always fast.
Once you've done all of this, and you've waited a month or so, a good follow up is to search your name + phone number, and name + address on every search engine (private browser session!) to find the remaining low-hanging fruit.
Find the opt-out form for anything you find, and follow up for every data broker you've opted out of to make sure they complied.