It is because "terraform init" needs some configurations to initialize your environment.
TLDR you need to create a tf file in your directory before running "terraform init" in your Powershell.
For example, in this section:
A provider.tf file is created first stating what provider I will be using, then only you "terraform init" it. So what terraform init does is it will download the required dependencies or "settings for Google" in the example above. Hopefully my answer helps you get started, else just let me know!