I need to insert this verification code into the index. I know WP is php but am unsure of where to insert the code. Would it go into the 'Main Index Template' (index.php)?
Add this meta tag to the <head> of your index.html file (or equivalent):
<meta name="p:domain_verify" content="e5fcf491d5b1d4d4db6690fd4ed553fa" />