howdythemes.com

Edit your style.css file

– How can I change the sub title font at the top of the page (the text underneath where it read Global@CU)

#logo .site-description {
font: normal 17px/1em Georgia, serif;
color: #ffffff !important;
}

The above code has white color (#ffffff)

So change that value. Use some colorpickers to get hexadecimal values

http://www.colorpicker.com/

– How can I put more of a gap in between the title and sub title of the site?

http://www.w3schools.com/css/css_padding.asp

How can I change the introduction text in the left hand side navigation bar (i.e. the text that reads ‘Globe@CU is an online platform for the promotion of international news stories…’)

wp-admin Dashboard -> Appearance -> widgets

Try the third solution of this article

http://wpsolutions.howdythemes.com/fatal-error-allowed-memory-size-of-67108864-bytes-exhausted/