I have never posted anything on a Home Page but there are news posted about myself, such as my acquisition of a badge. I don't know what information other people are seeing in my Timeline.

The news related to “badges” and “points” are only shown to yourself.

The “posts” that you have posted by yourself on your Timeline, as well as the comments that you posted on a study card, can be viewed by other users.

The visibility of such posts and comments are limited to the users who are studying the same course as you.