1) The name of the object is its name you have set up in the project bar.
If you have created a Sprite object and have not renamed it, it is "Sprite".
2) Plugins have common features one of which is to handle their UIDs and IIDs.
When you use the "Create object" action, for the remainder of the event, all actions related to the object type you created will apply only to the newly created instance.
It feels like you perhaps are asking the wrong question(s).
What are you trying to achieve, what have you done so far, and what would you expect your code to do ?
Clearly establishing those, we can provide actual insight as to how Construct works and how to effectively use picking for what you want to achieve.