Give us a few more details
I clicked on the Lightroom folder in my pictures folder.
What exactly did you click on? Give us the exact name of the file or folder or icon
When I tried to open it it said that folder was already in use?
Give us the exact word-for-word error message.
"The Lightroom Catatlog named Lightroom 5 Catalog cannot be opened because another application already has it opened. Quit the other application before trying to launch."
I got this message by opening lightroom. File- Open Catalog-Libraries-Pictures-Lightroom- then the Lightroom 5 Catalog.
The catalog I have been using for the past month is just called "new catalog".
In that folder, you need to find a file whose name ends with .lock, then delete that file (and only that file, don't delete anything else).
I am sending you a virtual hug! Thank you so much!