and 2nd "I am using Nostr (the protocol)." - a protocol able to create a "social" network "I have joined Nostr (the social network)," - or does anybody say "I have joined the Twitter/the Facebook/the Instagram/the Whatsapp"? Github (also no the) says -The simplest open protocol that is able to create a censorship-resistant global "social" network once and for all.

GitHub

GitHub - nostr-protocol/nostr: a truly censorship-resistant alternative to Twitter that has a chance of working

a truly censorship-resistant alternative to Twitter that has a chance of working - nostr-protocol/nostr