If anyone wants help with using this place or has any questions, feel free to ask! I'm trying to help new users especially!

Also, there is lots of info for beginners at https://fedi.tips (especially Quick Start at the top of the page).

I have a Q: if Mastadon is a Twitter dupe, Pixel-something an IG dupe, do I understand that “Test Flight” ( TF) is a TT dupe? If so, I’ve downloaded TF but it’s asking for a code?

Test Flight is a service run by Apple that lets people try out apps that are still in development.

Maybe you signed up for a test flight of Loops? It is asking for a code because you need one from the maker of the app to take part in the testing process.

Loops is run by @dansup but I think he is very busy with Pixelfed at the moment?