まず最初に

first of all

→ 先ず
phrase Rare #35,629
first of all Used to introduce the first point, action, or topic. The phrase combines まず and 最初に, both expressing the idea of doing something first, so it adds emphasis.
JA: まず最初に、自己紹介をします。
EN: First of all, I’ll introduce myself.

まず最初に現実をお話ししたいと思います

First of all, I’d like to talk about the reality of the situation.

まず最初にこの有名なを見ましょう

First, let's look at this famous painting.

本日まず最初に訪れるのはこの町で一番大きい神社です

The first place we’ll visit today is the largest shrine in this town.