The exact way to do this depends on your theme and the way the home page is set up.
In many themes, you can create a ‘sticky’ post that will stay at the top of the home page.
Create a new Post with the content you want in it. Then click ‘Edit’ next to ‘Visibility: Public’ over the ‘Publish’ button.
Check the box next to ‘Stick this post to the front page’ and click ‘OK’. Then click ‘Publish’.
That post will now show up at the top of the home page IF the theme supports it.
If you want the ‘About Me’ to show up in the sidebar, go to Admin->Appearance->Widgets and drag the ‘Text’ widget into the sidebar and position where you want it.
It is easy to put text into the widget, but a little harder to put in an image. If you want to do this, I will try to explain in another post.