Thumbnail & Posts Problem

Hello guys, i’ve got an wordpress news portal and i need to ask ask couple things. I use InspiredNews template by fthemes.

First of all as you can see in next image the post that i have been posted on my web shows whole the post in main page
https://i.imgur.com/74eYW.png
But i want ti be showed only the image and couple more links, all the other stuff should be read inside the post.

And secondly, i can’t get how can i add a thumbnail.. on my widget “most viewer” doesn’t appear any thumbnail, maybe i make sth wrong?

Thanks in advance, hope i was understandable.