Yes, there is a certification that tests the knowledge of Terraform. HashiCorp is the parent organization that rolled out Terraform, for building and maintaining infrastructure as a code. There is a certification named, HashiCorp certified: Terraform Associate exam, which you need to crack to become a Terraform Associate. You need to have sound fundamental knowledge in terminal skills, and a good understanding of on-premises, and cloud architecture.
If you wish to get certified in Cloud Computing, check out the Cloud Computing training course from a reputed e-learning company like Intellipaat. Watch the below posted video on Automate your AWS Cloud Infrastructure and get yourself started.
Check out the following video on DevOps Terraform Course to get a better understanding.