First of all, take a look at this document which describes the CoreMetrics mappings in detail: https://community.tealiumiq.com/posts/808305#events
Next, the way you're trying to use utag.link isn't quite correct. utag.link accepts an object as its argument, which should be a simple data object, and should not contain any function calls.
utag.link works as a kind of proxy to the native CoreMetrics methods, so it's no longer necessary to know the exact name of the CM method you wish to fire - Tealium will handle this for you if you set up the mappings correctly. In this case, I'd recommend doing the following:
"event_type" : "Click",
"element_id" : "123456",
"element_category" : "my category",
"element_attribute_1" : "some attribute"
You would then use the mapping toolbox to trigger the "Element" tag whenever "event_type" contains the value "Click", and you would map the remaining attributes to their respective mappings under the "Element" tab in the CM mapping toolbox in Tealium.
The advantage of using utag.link here instead of the native CoreMetrics method, is that should you decide to switch to a different analytics tool in future, you won't need to change the code on your site - you can just map the values to a different analytics tag inside Tealium, which is a quick and easy job.
I hope that all makes sense - it's difficult to explain the concept in a few paragraphs, so do reply if anything isn't clear.
Check out our new Swift integration library for iOS, macOS, tvOS and watchOS: https://github.com/Tealium/tealium-swift with updated documentation https://community.tealiumiq.com/t5/Swift/tkb-p/swift.