Since I've gotten some new followers, and some new folks have shown up, I think I'll re-post this:
I strongly suggest you follow @wtf, which is the help/faq account.
The most useful post here is this. It tells you how things work like how to send a private message and how the "omnibar" works. It has links to the system of markdown you can use to format your text, and the list of emojis. (Oh, and some people are using the bread emoji () to indicate mean "toast", as a kind of "like". )
Not noted there, but also useful: hitting shift and zero at the same time removes the follow notifications from your feed.