"here's how to install Graphene on a pixel and linux on a desktop" to break the ice and build the group.

I think the "what to look for in a phone" is great, but most people don't even really grasp the concept of an operating system as something different than the hardware, and will respond to the idea of changing it by freaking out.
You have to introduce them to Linux by giving them a machine already running it, which seems difficult in this context
It's also very difficult to get people to understand why they should care about privacy, let alone inconveniencing themselves to achieve it.
You could maybe show them how to use pcpartpicker? You might be able to find one or two people interested in building a new computer, and it kind of demystifies computers a bit.
You could encourage them to change their wifi password and make sure they don't use one password. Maybe talk about scams, things like short links in texts and such
But IDK, I'm in the comic too