Template Tag from function in Plugin class

This could be an issue with my PHP level.

I understand that if you make a function in a plugin:

function myFunction () {
 //function code here
}

Then you can call that function in a template.

However, I am trying to make a plugin following a safety standard to put the plugin functions in a class.

if (!class_exists("EnterClassName")) {
	class EnterClassName {
		function EnterClassName() { //constructor
		}

		function addFunction() {
			?>
				<!-- Place Function Code Here -->
			<?php
		}

		function addFunction2() {
			?>
				<!-- Place Function2 Code Here -->
 				echo "hello all";
			<?php
		}
	} //End Class DevloungePluginSeries

if (class_exists("EnterClassName")) {
	$nameInstance = new EnterClassName();
}

//Actions and Filters
if (isset($nameInstance)) {
	//Actions
	// add_action('hook_name', 'your_function_name', [priority], [accepted_args]);
	//Filters
	// add_filter('hook_name', 'your_filter', [priority], [accepted_args]);
}

So say I wanted to have function2 in a template I was thinking at the end of my code I could put:

function myTemplateFunction2() {
     print $nameInstance->function2;
}

And then I could put myTemplateFunction2() in my template file and this would cause “hello all” to show up in the browser. However, I am not getting any result. Nor an error.

Am I missing something?