Basic usage of Terraform with GCP
Step 1: Sign up for Google Cloud Platform (GCP) at cloud.google.com, using your personal GMail account, and create a "Project" in GCP.
Do you know what a Project is? It's a way to organize various GCP resources or something. Doesn't matter that much for this.
Step 2: Hunt around for the project_name, project_id, billing_account, and org_id, according to this recursive documentation (which refers you to more documentation):
Step 3: Rename the Terraform Variables file, named terraform.auto.tfvars.example to terraform.auto.tfvars, and keep it in the same folder as main.tf.
Step 4: Edit the file named terraform.auto.tfvars, and replace the default values with the stuff you hunted down in your Google Cloud account.
Step 5: Run terraform init
Step 6: Run terraform plan
Step 7: Run terraform apply
Step 8: Run terraform destroy to destroy all the GCP stuff you created.