Your first meeting with **had + past participle** — the form for the action that happened FIRST when you talk about two past moments. At A2 the goal is to recognise it and fix the common slip (using **has** or the plain past instead of **had**). You'll use it to tell full stories later at B1.
Practice tip: Spot the earlier past action and check its verb: it should be **had + done**. Fix any **has/have** or plain past back to **had**.