Refers to the very first step or initial stage of an activity, often with a nuance of 'to begin with' or 'as a start'. Commonly used in phrases like 手始めに.
手始めに、簡単な自己紹介をしましょう。
To start with, let's do a simple self-introduction.
彼は手始めとして、近所の掃除から始めた。
He began by cleaning up the neighborhood as a first step.
Let's start off by solving the easy questions first.
Starting with this project, the company plans to move forward with overseas expansion.