Clear journal pro = feature slider/content pictures size to change?

I use a clear journal pro theme which is really great. Though, I've got an issue with a size of pictures and cannot handle it myself. Firstly, how to change the width and height of feature content's and feature slider's pictures. Second issue is a HEADER size, it's way to height... Please tell me guys where to go to optimise it. Additionally, even though, the side has a DEFINITION OF THE PAGE LANGUAGE set to Polish while running sea auditor test, the result indicates there is any language defined. (settings>general>website language <-- there's set on Polish). My size is www.foodimport.pl