I am also a newbie to UiPath, I have also faced the same problem as of you. I have resolved it.
Try to follow these steps in the Input Section of the Properties Window:
1.Create a text file on any location.(Here, I have created on Desktop) (Eg: NewTextDoc.txt)
2.Specify the location of the file as the value to the Arguments field.
(For Ex: Arguments = “C:\Users\Netcon-Prabhakaran.S\Desktop\NewTextDoc.txt”)
3.In the selector field change the value of the title element to the name of the text file you have created.(For Ex: Selector = "<wnd app=‘notepad.exe’ cls=‘Notepad’ title=‘NewTextDoc.txt - Notepad’ ")
4.FileName will be generated automatically so you no need to change that.
For your reference, I have attached the project file.Notepad.xaml (16.8 KB)
With Best Regards,