I can't ungroup my vector
Hello,
I have downloaded a vector from the internet and opened it in Illustrator by going to File > Place.
I have tried the selection tool and the direct selection tool to highlight the individual picture that I want to use out of the vector, however none of this is working. It just highlights the whole document.
I have pressed ungroup, embedded etc and still nothing... I am new to illustrator so perhaps I'm doing something else wrong.

I want to be able to copy just the top line of stars and use them only. Does anyone know how I can do this?
ps. I am using Illustrator CC 2017.
