How to individualize posts?

Hello,
I’m using the convac lite theme. I recently started a blog and now I am wondering how it’s possible to individualize the posts: Each post contains automaticaly 4 little squares on the top of it:
-the first square shows kind of mountain and replaces, I think, a picture
-the second one shows the date
-the third one shows the profile of a person
-the fourth one shows the number of commentaries.

I would like to know whether it is possible to individualize these squares, especially the ones with the mountain and the profile. What are they standing for and how can I edit them?

Thanks so much for your help!

interstud