There is two questions.
1. The first is how to select required element. You can combine the locator selection by attributes and by hierarchical dom position. If you need practical examples to understand use cases there it is.
<span ng-show="$select.isEmpty()" class="select2-chosen ng-binding">Please Select</span>
If there is no other elements with same classname the answer for your case for select the element can be the next two (would find the same element)
Select dropdown = new Select(driver.findElement(By.className("select2-chosen ng-binding")));
or
Select dropdown = new Select(driver.findElement(By.xpath("//span[@class='select2-chosen ng-binding']")));
2. The next step is to select the one of the options in dropdown. For example, like @Hien Nguyen linked below, it would be
dropdown.selectByVisibleText("there is a text from option you need to select")
or the next lane to select the first option in dropdown
dropdown.selectByIndex(0)