Where do I find this as a kind of lesson or tutorial

Hello, i am a newb her and looking for help. I saw this on medium and I wonder where do find a equivalent or tutorial or how to for this.
As a newb I dont know where do find this subject, because I dont know the name for this? Its a box beside the main content.
I want that reads can like blogposts or and coment or save the topic too

Thanks in advance.