Catalog update

Help please! I have been getting the message to update my catalog like every other time I open Lightroom. I just assumed I had to because it doesn't let you do anything if you don't. I'm obviously not computer savvy with Lightroom but I now have like 30 "copies" of that same updated catalog. Problem is is it's an old one! I don't remember creating a new one but it's all older photos. I can not find my most recent catalog I was working in the past year. I've tried opening all of them and they all say it needs to be updated before I can open it. I can't go to most recent because I've been opening them all to try and find it. I updated my Lightroom the other day and now I can't find the one I was working in last. It just keeps wanting to update. I'm so lost on what to do! I've called Adobe support but they couldn't really help me find it. They just told me not hit update next time and just choose a different catalog. Also, last question can I delete all of these older catalogs since it has updated so many times?? It's taking up so much space. 

lastly I just realized my Lightroom was set up to not back up. Is that part of my problem?? 😞