Let's say you have an EC2 instance named "tc.micro instance 1".

This assumes you have setup Terraform as described in Amazon Web Services (AWS) - Getting Started with Terraform. 

Let's say you have the following files on your Terraform server.

├── required_providers.tf
├── ec2 (directory)
│   ├── data.tf
│   ├── outputs.tf
│   ├── provider.tf
│   ├── resources.tf

required_providers.tf will almost always have this.

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
    }
  }
}

Let's say provider.tf has the following. In this example, the "default" profile in /home/username/.aws/config and /home/username/.aws/credentials is being used. This assumes you have setup Terraform as described in Amazon Web Services (AWS) - Getting Started with Terraform.

provider "aws" {
  alias   = "default"
  profile = "default"
  region  = "default"
}

data.tf could have something like this.  In this example, tag:Name and "t2.micro instance 1" is used to find the instance tagged "t2.micro instance 1".

data "aws_instance" "my-instance" {
  filter {
    name = "tag:Name"
    values = ["my-instance"]
  }
}

The terraform refresh command should then output something like this.

my-instance = {
  "ami" = "ami-026b57f3c383c2eec"
  "arn" = "arn:aws:ec2:us-east-1:123456789012:instance/i-03870f20800891c34"
  "associate_public_ip_address" = true
  "availability_zone" = "us-east-1b"
  "credit_specification" = tolist([
    {
      "cpu_credits" = "standard"
    },
  ])
  "disable_api_stop" = false
  "disable_api_termination" = false
  "ebs_block_device" = toset([])
  "ebs_optimized" = false
  "enclave_options" = tolist([
    {
      "enabled" = false
    },
  ])
  "ephemeral_block_device" = tolist([])
  "filter" = toset([
    {
      "name" = "tag:Name"
      "values" = toset([
        "my-instance",
      ])
    },
  ])
  "get_password_data" = false
  "get_user_data" = false
  "host_id" = tostring(null)
  "host_resource_group_arn" = tostring(null)
  "iam_instance_profile" = ""
  "id" = "i-03870f20800891c34"
  "instance_id" = tostring(null)
  "instance_state" = "running"
  "instance_tags" = tomap(null) /* of string */
  "instance_type" = "t2.micro"
  "ipv6_addresses" = toset([])
  "key_name" = "default"
  "maintenance_options" = tolist([
    {
      "auto_recovery" = "default"
    },
  ])
  "metadata_options" = tolist([
    {
      "http_endpoint" = "enabled"
      "http_put_response_hop_limit" = 1
      "http_tokens" = "optional"
      "instance_metadata_tags" = "disabled"
    },
  ])
  "monitoring" = false
  "network_interface_id" = "eni-04bfc54ff3158b01a"
  "outpost_arn" = ""
  "password_data" = tostring(null)
  "placement_group" = ""
  "placement_partition_number" = tonumber(null)
  "private_dns" = "ip-172-31-87-28.ec2.internal"
  "private_dns_name_options" = tolist([
    {
      "enable_resource_name_dns_a_record" = true
      "enable_resource_name_dns_aaaa_record" = false
      "hostname_type" = "ip-name"
    },
  ])
  "private_ip" = "172.31.87.28"
  "public_dns" = "ec2-18-234-187-17.compute-1.amazonaws.com"
  "public_ip" = "18.234.187.17"
  "root_block_device" = toset([
    {
      "delete_on_termination" = true
      "device_name" = "/dev/xvda"
      "encrypted" = false
      "iops" = 100
      "kms_key_id" = ""
      "tags" = tomap({})
      "throughput" = 0
      "volume_id" = "vol-0ef385c7b3d5c6f8b"
      "volume_size" = 8
      "volume_type" = "gp2"
    },
  ])
  "secondary_private_ips" = toset([])
  "security_groups" = toset([
    "default",
  ])
  "source_dest_check" = true
  "subnet_id" = "subnet-0316e4d9fcd4efccc"
  "tags" = tomap({
    "Name" = "my-instance"
  })
  "tenancy" = "default"
  "timeouts" = null /* object */
  "user_data" = tostring(null)
  "user_data_base64" = tostring(null)
  "vpc_security_group_ids" = toset([
    "sg-0c3296b3cd153fdc1",
  ])
}