When you get the echoes and noise solved, you might try AudioBook Mastering 4.
https://forum.audacityteam.org/t/audiobook-mastering-version-4/45908/1
That will take you from a raw, clean reading to a finished audiobook chapter. It solves all the technical problems but noise.
If you have a quiet setup, you may be done.
If you’re following a different system for mastering, then the rules change. You can’t put Noise Reduction at the end and post production tools get harder to manage.
Koz