To remove the phrase 'Please join us to celebrate our wedding on January 1, 2016' on your wedding website, just simply add the CSS code below to your website.
#wedding_date_title{
display:none!important;
}
#wedding_date{
display:none!important;
}
To add the CSS code, just simply go to your website editor and open up the "SITE EDITOR MENU" option and click on CUSTOM CSS.