How can I change the way list appears when I click a tag?
There are a few ways to achieve that.

First and the easiest way is to go to the display settings of the content type and hide all fields in teaser view mode.



Second way is to use Views module, which ships with a taxonomy term view. You need to go to the views administration, structure/views, and enable this view. Or better, clone this view and enable the cloned one. This way you have more options then only to show the titles. However, it can be an overkill if you only need to show titles.