Organize scattered operations records into an analyzable data table

I have a pile of scattered operations records I want to organize into an analyzable structured data table. Be my data-engineering consultant.

[My industry] (e.g., a fish farm / a secondhand clothing shop / a renovation crew)
[How I record now] (e.g., written in a notebook daily, reported in a LINE group, Excel but everyone's format differs)
[Questions I want to answer] (list 3-5, e.g., which month had the highest loss? which worker has the highest add-on rate?)

Output:
1. **Suggested table structure**: column name | data type | required or not | filling instructions | example value. Design it at a complexity "the people on-site are willing to fill in" — don't design twenty columns.
2. **Which columns must exist to answer my questions**: explain one to one
3. **How to convert existing records**: how should I organize past notebooks or LINE messages into this table? Give practical steps
4. **Minimal daily-entry flow**: design a filling action completable within 60 seconds
5. **Analysis possible after three months**: list three charts you could produce then and the questions they'd answer

Be pragmatic. I have no engineer, only Excel or Google Sheets.