What. I don't think you understood me. Let me try again.

You just move forward and say hi along the way. That is all. You write a regular post to move the plot forward and somewhere in there add "oh and by the way my name is Jimmy Junior Senior San Sama." And that is all you need to do.

If the Rp is set up in such a way where it drags out intros otherwise and gives players no options for just moving forward, we have a term for that. Railroading. Choo choo mother!@#$er, you get no choices, you must move at the incredible terrible and entirely inorganic pacing set by the guy or gal running the show, who probably has complete shit tier writing.