Blog posting info

Hi there
I have been altering fonts slightly with this theme which I now realise I should have done in a child theme. I have one problem that I cannot resolve. Where the blog posts appear – the information under the title such as the author, when it was posted and comments headings are in uppercase and almost illegible. I was wondering how to change this? I have tried lots of different options in stylesheet but can’t find the one to change this bit.