To get values out of a cluster, use the cluter functions. Specifically, unbundle and unbundle by name. If you want to detect your click, you need to use an event structure with a value change event for the cluster. Look
here for an explanation of event structures.
To get a value from an array, you use the "index array" VI. When you wire an array into it, it will grow to the proper size.
To find more functionalities, I suggest you try searching this site and google for LabVIEW tutorials.
Here is one you can start with. You can also contact your local NI office and join one of their courses.
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