Shell Script Rewrite - It is simple shell script.- Actions Involved CREATE/FIND/REPLACE

Job ID: 34273183

Budget: ₹1,000 – ₹1,500 INR

I have developed a simple shell script program with all functional requirements and it is working fine. But I have built up those with my basic knowledge (sequential manner) with the help of Google. So I want to be rewritten in the proper way considering the below points
Rewrite code as it looks like an expert, not a beginner.
Remove configurable values from the code and place them separately outside the code as a config file and make use of it.
Variable names/Indentations
Emailing Feature needs to be added I have code for emailing already but not sure how to add it, which needs to be done.
Gather inputs from Excel. Currently, it is taking from csv.
Logging/Transactions are missing which needs to be added.
Few other things if necessary.

Note: The existing script is working fine we are just rewriting it to make it better like expert level.