Can I use Github to showcase the mini projects like blog-app, Amazon clone, etc that I have developed while practising newly learned technologies?

Straight answer Yes.

Github is primarily a web based Git Repository hosting. It provides all features of Git like version control and source code management (SCM). It hosts largest code base in the world.

Yes, free accounts are used mainly for open-source contributions. Being said that, there is no hard and fast rule to limit its features only for well-grown projects. And hundreds of open-source projects were once started as samples. GitHub’s motto is “Build software better, together.”, “Where software is built”. Thus, the code you share would be actively visited/improved/used. Who knows one of the ideas you start in github might be a seed to the most used open-source library in future.

And the terms of service doesn’t enforce the repository to be open-source. So, you can add License file to your repository in case if you want no one to use your source code (but you cannot restrict in real-time, unless you have a private repo.).

GitHub Gist can be used if you want to share a small piece of code not an entire project.

Hope this helps!

Happy coding.