Backup your stuff
Iirc theyre these expensive discs that are highly resistant to disc rot (or something along those lines) for at least 1000 years. Kinda gimmicky tbh since it still needs to be stored properly to achieve that claim and suffers from the same problems as any other optical disc (the equipment needed to read and write and still durability)
Regardless of os full disk encryption is your friend and keep regular backups incase shit hits the fan. Rely on bookmarks as much as possible to minimize your chances of clicking on phishing links and stick to trusted sites. Lastly use a trusted vpn with a killswitch even if you dont think you need one it never hurts.
Sadly dont think you can buy locally from a store but only through their website, they’ll deliever to the address that you put so maybe use someone else’s and just pick it up like a friend’s or family member’s. Think they also do esim but im not 100% but if they do that would be emailed so no waiting
I made a separate user profile just for my social pwas since I use grapheneos. They’ll probably use discord or whatsapp so treat it like a public forum, stick with alias emails, fake info when creating, an always on vpn, and within a browser thats has privacy hardened features. If they want to talk more privately like through direct messaging and you trust them then try to convert them to signal otherwise simplex works too if you dont trust them with your personal phone number
Edit: Im not sure how instagram is these days but I guess you can make a burner using the same steps I described just dont actually post anything and dont add any identifying info haha. Have fun and good luck on the friend search
Oof sorry can’t help you there. I mostly just stick to the camera thats stock on grapheneos. Think its available for other devices so maybe check it out?
Edit: looks like it Is