You are learning the full market shop: you will read the scene it happens in, learn 10 words and phrases, take apart the pattern behind them (先~然后 sequence + shopping completion), hear them in a conversation, rehearse them, and finish by saying one thing out loud to be graded.
Sunday morning at a Shanghai 菜市场 — four stalls, a complete week's shopping, everything paid by QR code. 150 words, three units, Shanghai is yours.
Sunday 7:30am at the Jing'an market. The stranger now has a system: vegetables first (the stall by the entrance, the woman who always gives him an extra bunch of scallions), then proteins (the fishmonger in the back who speaks the fastest), then fruit (the young couple by the south exit who play music while they work).
「先买蔬菜，然后买鱼，最后买水果。」 He says it to himself, in Chinese, and feels pleased about this.
At each stall the vendor recognizes him now. 「来了！今天要什么？」 (You're here! What do you want today?) This is Shanghai market belonging — you come back and they notice.
An hour later, bag heavy: 「买完了！」 The vegetable woman waves as he passes. 「常来啊！」 Come often. 「好！下周见！上海太好了！」