When promoting event on social media, there are basic elements that we recommend to always feature in your posts. These include:

Name of the event
Location
Date and time
Information on what the event is about, and who it is for
Instructions on how to join (link to more information, details on how to buy tickets, etc.)
An attractive and clear visual to capture attention (image, video, carousel, etc.)
Your event or company logo, and any additional branding
A unique event hashtag (to group event posts together, and allow people to easily find more information)