My opinions are likely to be in accord with information found at https://www.privacyguides.org/en/desktop/ and https://www.privacyguides.org/en/android/distributions/

As an alternative to making decisions without direct assistance, you might benefit from contracting with another person to make decisions based on requirements you describe (essentially getting a chief information officer (CIO) for yourself). The main reason I'm suggesting this is that having more people involved will make it more likely that someone will know about established best practices relevant to your situation or that someone will have experience with a problem that is similar to the one you're dealing with. Additional reasons I could provide for this would be similar to the reasons people give to discourage someone from handling court appearances without a lawyer or doing surgery on themselves. You might be able to use https://ryf.fsf.org/categories/laptops to find information about how to contact people about your computing needs. Alternatively, you could visit a store (for example, one operated by Walmart).