GitHub Actions is free for public repositories, and that not the case with the private repositories as they are given a share of free minutes and storage capabilities. Crossing which, they will be charged depending on the product used with the account.
Check out our Git training course from Intellipaat which is a course of 16hrs with 20hrs of training through projects and exercises.
Also, do check out our YouTube video on GitHub Workflow Tutorial to help you better understand the workflow and how it makes the whole process efficient.