Thanks for posting your campaign! You have done a great job adding in your Social Media links in an easy to see place, as well as having your images be clickable links. Here are some suggestions for you:
Your calls to action are good. Have you tested other variations before to try to create a sense of urgency? For example: Call to reserve your spot today or Limited space - Call to RSVP Now.
After taking a look at your site I might recommend matching your emails to the colors/layout on the site. This would create consistent branding across your digital presence.
The length of the email is a little long. I would recommend using a Table of Contents, to let people know what is in "This Issue." Or seeing if there is content that you can move to the left side bar to help shrink the email.