phrase
A2
beginning with the most important or earliest thing
First of all, we need to decide on the date for the meeting.
首先，我们需要确定会议的日期。
A2
introducing the first point in a list or explanation
First of all, let's discuss the budget; then we can move on to other topics.
首先，我们来讨论预算；然后我们可以继续讨论其他议题。
translation
首先