Hi Heather. Yes, you can use the old version of Lightroom, or Lightroom Classic is the latest version of the "old version of Lightroom" which looks basically the same but hopefully a bit faster with a couple of extra features.
Tell us what you can see right now and exactly what happens. Which OS are you using?
All we need to do is find your catalog. You can search your computer - it'll have a *.lrcat extension.
My best guess is your catalog was stored on an external drive that's not connected now, or that's changed drive letters. Does that ring a bell?
I searched for that extension and nothing came up. The photo shop version is all different now too. Is there a way to get the older one back ? I still don't know where to find the old catalogue for light room. DO I select import and then search? I wish a rep could come to my house and give me a lesson one on one. I'd pay so much to ask the questions I want to know!!!!
Yes, you can go back. In the Creative Cloud app, if you click the arrow to the right of the Open button and it'll say Other Versions. That's where you'd click to install older ones.
That won't help get your catalog back though. The question is where did you store it. Don't go to import and then search. Just use your operating system search for look for the files. That's Windows Search on Windows, or Spotlight on Mac. When you find the catalog, then you just double click on it to open it into Lightroom.
Don't suppose you usually have an external drive plugged in? That's a likely suspect, if you have deleted files from your computer.
There are people who do one on one training, although it's not free. I do training online over screensharing, but I'm tied up writing at the moment. Laura Shoe and Rikk Flohr are another couple of experienced teachers who spring to mind.