CircleCI 101
Today there are many CI/CD options. Most services include some CI/CD services in their free offer (like GitHub and GitLab). Alternatively you can host your solution with Jenkins and avoid using a online service. But even with such a fearse competition, I think CircleCI free offering is an interesting choice. The documentation is amazing, it has SSH debugging, and lots of solutions that you can use (ie. AWS CLI ORB).