You can hear this English expression in a meeting. If there are announcements to make, people to introduce, or other things to talk about before the main topic of the meeting, someone will say "Before we begin...":

Before we begin, I wanted to introduce everyone to a new member of our team. This is Hyejin Lee.

The host of a TV or radio talk show sometimes uses this expression as well.

This expression is very close to "Before we get started..." but is a little more formal.