首先……其次……
shǒuxiān… qícì…
Meaning
首先……其次…… presents ideas, reasons or steps in sequence. 首先 — first, first of all 其次 — second, next
This pattern is common in formal and written Chinese.
首先……其次……
不管做什么事情，首先应该明白你为什么要做，其次要知道怎么做。
Whatever you do, first understand why you're doing it, and second know how to do it.
首先，要穿正式的衣服，这会给面试者留下一个好的印象。
First, wear formal clothes — it leaves the interviewer with a good impression.
其次，应聘时不要紧张。
Second, don't be nervous during the interview.
首先 as an adverb
Used alone it means “first of all”, “before anything else”.
不管以后做什么工作，你首先应该有一个好身体。
Whatever job you do in future, the first thing you need is good health.
很多人遇到不明白的地方，首先想到的是上网查一查。
When people run into something they don't understand, the first thing they think of is searching online.
首先 vs. 第一
我是第一。
I am first.
第一课。
Lesson One.
首先 → organises ideas or steps: 首先……其次……最后……
第一 → a rank or ordinal number.
首先 = first of all
其次 = secondly
Mostly formal writing and speeches.