> How will they develop “street smarts” about being on social media without a social media account?
"Don't trust strangers; they only want to humiliate, rape, or kill you" works well enough. Same as reality, the problem with social media is the people.
The "street smarts" kids have picked up from social media access is nothing to celebrate. /r/runaway is a very sordid place encouraging kids to hook up with total strangers. Rate of teen suicide has only increased since the invention of social media. Kids are exchanging scamming tactics and teaching each other how to maintain eating disorders covertly and fake illnesses convincingly enough to fool doctors.
Give them a book and a Python interpreter. Plenty of us got started that way, and some of us still have to work that way-- in SCIFs or other air-gapped environments with no internet access.
> How do I let them have the same positive experiences I had playing games without having the deeply negative ones too (I lost that breastplate that took weeks of grinding to get because the Bloodwood forest swallowed my corpse).
What does this have to do with the internet?
Everyone has lost local saves due to bugs, power outage or corrupted media. "Save early and save often" was a lesson taught by a creepy middle-aged guy named Larry Laffer, using entirely-offline software bearing his name.