This is a vital part of your book. While many writers spend a long time, perhaps too long on the first sentence, what’s most important here is the first chapter altogether. It’s not just about your first sentence, so forget that.
But, you do want to make sure you’re using this first chapter to setup your character, what their life looks like, as well as an introduction to the potential conflict in the book.
If you can foreshadow any twist you have planned for your climax, doing so in this chapter can be GOLD to your readers.