if you are New and wish to know which order to play, first of all "Hi!" hope you are having a great day cause things will get depressing, and second i recomend this order:
Leo
Carl
Jenna
TJ
Flynn
the main core of this game is learning about the characters and this order will give you a more consistent story and you wont have to piece toguether to much of each character and lore by playing it this way.
I recomend Leo first cause you're in for a rude awakening, and Flynn last cause it is the most confusing if you haven't played the other routes first, and because i want you to finish the game feeling hopeless and depressed XD
mind you this is my prefer order, you could also go:
Carl
Leo
TJ
Flynn
Jenna
as this is the order the game gives you in the extra and the order the developers took when making/finishing the game. It is also consistent and will leave you with a more "happier ending" to end on if you are a coward.