You can dual-boot if you don’t want to go all in? Not sure about laptop dual boot but that’s what I do on my desktop.
I’ve had a family member complain about “another chatting app on their phone”, but if you convince them that they can only really contact you there (because YOU are deleting everything else off your phone), they’ll do it and see that it’s absolutely fine.
Re Linux: Do you want to be tech support for these people when they accidentally brick their system or they have a file compatibility issue when using Libre Office and collaborating with someone using Word? Linux is easy for people like us that are interested in tech as a hobby.
Normal people sit in the paradigm of just wanting their tech to be as user friendly and railroaded as possible.
I’m sure those people have hobbies, and preferences about those hobbies, that might benefit you if you knew. How would you want them to convince you that, say, changing the oil on your car is actually really quick and easy if you know what to do?
I don’t mean to be obtuse, this is the reality of trying to onboard people that aren’t fussed about privacy. They’ve generally got their own thing going on and don’t want to dive down a new rabbit hole.
Edit: For some actual advice: start with your partner and close friends/family.
Of the friends which you are talking to about it, target the ones which are more likely to already have an existing predisposition to caring about privacy.
Just get them to use Signal for now. Say that you’re deleting WhatsApp or messenger or whatever it is that you use to communicate with them generally and ask them just to install this new one that is more privacy-respecting.
If you can get people off of Facebook Messenger or whatsapp as the default messaging app, that is a huge win. People tend to share their most personal secrets in what they assume to be private forums. Most people don’t post that much stuff to Facebook’s wall anyway anymore.
If the person that you’re speaking to might distrust the government more than Mega-corporations, focus on the fact that the government can access those corporations’ data pretty easily. If the person that you’re trying to convince personally finds musk or Zuckerberg gross, then lean into that.
Don’t even bother talking to Sarah from accounting at work about privacy.
Ah yeah that’s a predicament. Do you know what distro you are going to be using? If you haven’t decided, Fedora with GNOME as the DE is a good bet. Otherwise Zorin or Ubuntu, again with GNOME. Apparently that DE is better for devices with touchscreens.