When I talk to Hashicorp or AWS they provide tooling specifically for GitHub Actions. I don't see the same level of vendor commitment when it comes to GitLab. If I'm not going to get vendor commitment I might as well run buildkite which is awesome or even look to something like Tekton for Kubernetes if I'm just doing Kubernetes anyways.
I'd recommend starting with one of the workshops listed here [0] and maybe dive into more learning resources and the documentation.
Our community platforms, such as the forum [2] and Stack Overflow, etc. [3] are also a great place to ask questions and collaborate on challenges.
[0] https://about.gitlab.com/handbook/marketing/community-relati...
[1] https://about.gitlab.com/learn/
[2] https://forum.gitlab.com/
[3] https://about.gitlab.com/community/