Adding items to a post in the archives page

So I’m trying to figure out how to do a few things – but asking one should answer them all I would think. I want to add some icons (through CSS via a span tag) to certain parts of a post that show. Such as date, author, etc. Where do I go to find that?

Or…should I be doing some kind of function so that it’s not all overridden if I update WP?

I also want to be able to add the “post type” to the content – such as image, video, post, standard etc.

Let me know if I’m making enough sense here or if I need to provide more details.