Sorry for the easy (to everyone but me probably!) question--I have tried to search the Calibre forum but can't find the easy explanation I need

I have a Dropbox account--I got it a while ago and never did anything with it, but would like to put my calibre library on it.
So, anyway, I just want to be sure I am not deleting my library

or something equally horrible. So I would go to the library icon and "create library" , send it to a new location (C:\Users\
my name\Documents\My Dropbox, and "use the previously existing library at the new location"?
I feel it can't be that easy and I'm probably missing something

So somebody please tell me yea or nay as to whether I have figured it out.
Mary