I had borrowed 2 books from the local library yesterday and had them transfered to my Kobo e Reader

I borrowed 2 books from the local library yesterday and transferred them to my Kobo e reader , with adobe digital editions. When I just clickedob the adobe icon on my desktop. to return one of the books , they are not there .  so where are they gone . It also says that I don't have any books borrowed ,but the books are on my Kobo reader. Now I am an old 75 yr old woman and I am not up on these new technologies , so I don't know what to do.