Follow the extremelly well documented 'Get Started' from HashiCorp Learn.
Visit https://learn.hashicorp.com/terraform for more info

After installing Terraform CLI and you cloud provider SDK, as well as properly configure your credentials do the following:

• Create a directory

• Create your main.tf configuration file

• Apply the following:
  terraform init

• After finish your configuration file format it and validate it:
  terraform fmt
terraform validate

• Plan and review the staged changes prior to apply:
  terraform plan

• Apply the changes and deploy the infrastructure:
  terraform appy
  Type 'yes' and hit enter

• After deploy all infrastructure remember to rollback all changes (specially for not get charged too much for any resource):
  terraform destroy

• Sucessfuly deployed a docker container with Terraform CLI
• Complete destroy infrastructure resources after learning session

• Successfully deployed a EC2 instance with Terraform CLI
• Successfully changed EC2 AMI and tag name
• Complete destroy infrastructure resources after learning session

├── README.MD
├── learn-terraform-aws-instance
└── terraform-docker-demo