Why do I have several tracks (and empty space)

Why do I have several tracks (and empty space) in one recording? I must have set something up incorrectly.

And, any idea why the ACX check says noise floor is too low? (this doesn’t happen all the time, just a few times recently)

Any help on adjusting the RMS would be great too. I’ve moved and set up a new tiny booth…have been using Audacity for past two years. It’s a workhorse and has been a great help for my narration work.

Best,
Linda