@dringer Thanks very much for your question!
The first thing you need to understand when parsing JSON from the server is that you’ll need to connect to a REST API from your app using Apple’s URLSession API. Assuming you don’t need any help with the networking portion, then I would STRONGLY recommend that you learn how to use the “Codable” protocol which was just recently introduced in Swift 4. A good starting point would be to go through the following article.
In a nutshell, create a struct class which implements the Codable protocol, and model it after the JSON data that you are receiving from your REST API. Then using your networking code, decode the data object that you receive from the cloud into an array of these struct model objects, and then pass it back to the class which is the DataSource for your UICollectionView, and then iterate through the array and display the contents.
I hope this helps!
All the best!