How to send a group msg on iphone?

I mean one where everyone can talk to everyone, not just me talking to everyone and everyone only talking to me.
For example, friend A can talk to friend B, and I can talk to friend B, and friend b can talk to friend c, and so on.

You should be able to go to Messages app then press the new message button and type in the names of everyone you want to be in the group message. After that, just type your message and send it. It will be sent to everyone and it will form a conversation in which everyone can reply to each other and everyone will be able to see everyone else's messages. I think people who don't have iPhones may only be able to reply to you

Simple, go to the text messages app. Then, type in one person's name. After it shows up, type another one's. Easy. It'll automatically be titled, "Group," "Group 2," etc. Everyone'll be able to talk to each other. On the screen, it shows each person's name on the particular message. (when each person says something) Good luck!