Instagram and Google would not even have their SSN or credit card number (if OP is being honest about how little they used those accounts), so I don't see how you can conclude that one of those is the factor...

the google one is normal if you haven't logged in in years, especially if you're in a different place now. Google is perfectly happy to lock people out of their accounts with the correct password

Instagram, Google and Twitter probably have a different cause. Everyone gets accounts disabled on these services, if one doesn't use them often.

It can feel like you're being attacked with a list like this, but it's highly likely the tech items are just coincidence.

Shouldn’t requesting the free credit report from each bureau be the first step before going to the paid one?

Absolutely - don't use the paid one ever, that's basically submitting to their protection racket. It's a problem they created in the first place.

You can check your credit for free, and the freezes are also free.