Volatile161 thanks for wanting to make a difference in other people's life. I think it's important that you take it slow and easy on the people. Don't make extreme claims or push anyone to change their lifestyle against "evil big tech" or any such comments.
Play the nice and humble card. Be honest that you discovered GrapheneOS not long ago and are on your own security and privacy journey. Link to videos from The Hated One, Side of Burritos or podcast episodes from Michael Bazzell, let them be the experts to explain details and have people get informed through their entertaining and well produced content. You don't want to be the evangelist that everyone turns away from, but the nice and approachable beginner that people can be eye to eye with and relate to.
Make your posts personal, let them know about your mistakes and what GOS has provided you with and what you are specifically most grateful for. Also make sure to let everyone know what GOS is not. It's not a magic pill for full security, privacy and anonymity, you need to learn good habits alongside. It's dangerous if you don't have a threat model because you easily go crazy and paranoid. It's not protecting you from all the reduction in convenience and living the privacy lifestyle is a marathon and no sprint, so let everyone take it slowly.
At least that's what I do and would recommend you doing. Let people make their own decision, don't judge them if they want to stick to their iPhones and Samsungs (it's already a big win if they for example start using Signal over WhatsApp or Brave over Chrome). Provide them with easy information so they are empowered to make an educated decision for themselves, and then respect that decision. I'm not speaking for GOS, but I'd assume the devs don't need a mass of uneducated people looking for the quick and easy solution to all their problems. The devs could use some curious, knowledge-hungry people willing and able to support them with their money, time and talents though...
That's my 2 cents, thanks again and have fun continuing your journey. You're on a good track and I'm impressed with your communication (especially on that Linux Distribution thread of yours), so if anyone can make a big difference, it's people like you.