Catalina do loop
New out of the box MacBook Air asked to update to Catalina. Since the update started, I've gotten the Apple Symbol, a progress bar that goes about 90% and then it restarts. How do I get out of this loop?
Even though your Mac obviously turns on, begin with If your Mac doesn't turn on.
Read and follow each of its steps, including all the links within it, all the way through and including Step 4, which directs you to:
If your Mac starts up to a blank screen
Read and follow each of it steps also, all the way through and including the end, which takes you to:
"If you still need help, please contact Apple Support."
Your Mac is new, so support will be complimentary.