They have different meanings. A native speaker will use each form in the correct context. Time to consult a grammar book.
- What did you do? (What did you <verb bare infinitive>?) Simple present. Question form for a completed action during a completed time period.
- What have you done? (What have you <verb part participle>) Present perfect. Question form for a completed action during an incomplete time period ending in the period.
- What had you done? (What had you <verb part participle>) Past perfect. Question form for a completed action during a completed time period prior to another event in the past.