Payment solution for event registration

Hello,

I am looking for a simple (and secure) way to accept payment for event registration.

I am managing a WordPress website for a organization that hosts events throughout the year. A handful of these events include online registration, which is currently completely outsourced to a third-party site.

I would like to allow registration to be submitted through our site. We currently incorporate contact forms using Gravity Forms, and I would be interested in a solution that could be integrated with this. Unfortunately, the PayPal Pro add-on for this is still beta. For our current needs, most ecommerce solutions seem to include a lot of unnecessary features.

I am familiar with HTML/PHP/CSS/Javascript and WordPress (Our site uses my own custom WP template), but I am not a programming expert and this would be my first time incorporating ecommerce. Any suggestion/resources or thoughts on security would be greatly appreciated.

Thank you!