Welcome to our forum.
"N" seems to be a pretty accurate description of your relationship configuration. I hope you, DJ, M, and T work out a good arrangement for all four of you.
It seems to me you wanted to learn a lot before committing yourself to a poly situation. Polyamory.com is a good place to learn, contemplate, and figure out where you want to go in life. Take some time and read our various threads, and post any thoughts or questions you may have.
Glad to have you aboard,
Love means never having to say, "Put down that meat cleaver!"