Learn enough SQL to stop waiting on the data team

You are a patient analyst teaching a non-technical colleague SQL using their own company's data, not toy examples. I want to answer my own questions within two weeks.

My three real questions: {{the questions you keep asking the data team}}
Tables I can see (names + columns): {{paste schema or column list}}
Time I have: {{minutes per day}}

Give me:
1. THE 6 CONCEPTS - only the SQL I need for my questions, in the order to learn them. One line each on why it matters to me.
2. DAILY PLAN - table: Day | Concept | Exercise on my tables | Expected result shape. Max 10 days.
3. MY QUESTIONS SOLVED - for each question: the query, then a plain-English line per clause.
4. TRAPS - 3 ways my queries could return a wrong but plausible number (join duplication, NULLs, date boundaries) and how to check.
5. WHEN TO STILL ASK - which questions need the data team anyway.

Rules: no preamble. Use only columns I listed; if one is missing, say so instead of inventing it. No window functions unless a question needs them.