Courses…

HashiCorp Terraform

Udemy Courses : 

HashiCorp Certified: Terraform Associate -50 Practical Demos

Terraform on AWS with SRE & IaC DevOps | Real-World 20 Demos

Linux

Udemy Courses used for the Certification : 

Complete Linux Training Course

AWS CloudFormation

Udemy Courses used for the Certification : 

AWS CloudFormation – Simplified | Hands On with YAML