Show author+avatar on Main Page

I just moved my page from Twenty Sixteen to Twenty Seventeen. I’m really happy about the new template, but since my site is a multi author blog I’d like to show the author’s name, his avatar (and maybe even the categories) of each post on the Main Page… just like in Twenty Sixteen (on the left of the content). Is that possible? Why aren’t such simple things (at least: show author’s name) customizable through the Customizer? Maybe a plugin for this?