Howcan i change the blogpost preview in the network theme

hi I just installed the network theme to build my layout. I got some questions about the post previews:

-there is an article picture with text under it, is it possible to have the pic left and the text right? i cant find the files..

-the preview text is very short can i decide somewhere how long it is?

this is the status:
and how it should look:

Thanks, Kev