First ~66% is about parsing arguments in a script (without treating the subject really), and the last ~33% is about set -euo pipefail (a mandatory line to any half-serious bash script). It's a nice read, with accurate and important information. But the intro seemed too verbose to me. And, the text was presented as being mostly about the last third. I have found this a little bit confusing, idk what would be a good intro to `set`, maybe some counter examples would be better. Then the first 66% should be another post entirely, with better treatment to the material being taught (case statements, parsing args from cli to script)...
My advise is to use Python instead of Bash. Don't be a hardcore programmer, Just get work done and go touch some grass (: