You would enter the name of the event in the title (above) and then you can write about it in the article body here.
There is a 'Featured Image" field you can use to set the main image for the event. You would also drop in your images here and add any additional copy that you want.
Finally, you can 'categorize' your articles / event posts by adding tags to the article. For example I have tagged this post "Track Days."