This support article covers most of the onscreen options/explanations which I think is what you are mentioning - not sure if its 100% current.
Some of this stuff is also replicated on the Companion App to save fluffing round with a mouse while riding.
If anything is missing, grab a screen capture or photo and post it up - plenty of people will be hapy to explain/point you to good online docs/vids.
And yep, Zwift is a bit of challenge to get your head around when you first get going. Someone can probably point you to a new users guide somewhere (I have no clue if one exists) but another important thread in these forums is a Wiki that a member built up over the last 6 months or so or heaps of useful things - book mark this: