Hello folks. I'm just chiming in as a regular member that is a moderator on another large forum that went through a vBulletin to Xenforo transition. I get that all the buttons look different and are in different places. PMs are called conversations, and its all just new. I've been using the XF platform for several years now, so if you have any questions, just ask, no matter how simple.
Jump to last post, newest unread post, invite new members to a PM (conversation), leave a conversation, quote, multiquote, quick quote, partial quote, embed images or videos, attach videos, save / delete draft posts, or whatever. Just shoot me a PM or ask in a thread (is there a good thread for this purpose already around?).
I haven't poked around to see what options are turned on or off, or what plugins are being used, but for the most part I know how most of the buttons work and where they are.