I see you have been getting along fine without me!
Yesterday was a busy day - in fact John I could have dropped in to say hello yesterday afternoon as Julia and I were at Maggots End, near Bishops Stortford, to pick up some more rescued ex-battery hens, and then I was off to Park Cameras in West Sussex, so about 250 miles all told in the car!
Back to Lightroom, I think the best thing to do is to import a small selection of images to start off with.
1. Open the Import box via File > Import or click Import button in the Library, or simply drag and drop a folder or file onto the Library display. If you are importing a folder, check the box that says sub folders too if you want all folders imported.
2. In the Import box, examine the right hand panel carefully and choose the options you wish. I can look at these in detail later if necessary, but basically here you can choose where the imported files go, whether they should be renamed according to rules, whether pre-set metadata should associated (name, copyright, location, etc.), the size of generated previews, etc.
3. Once you have a growing library you may occasionally find that some of the selected images previewed as thumbnails in the import box will be darkened and un-checked. This is because (if set in preferences) Lightroom has identified that these images duplicates with an original already in the catalogue you are importing into.
4. I haven't touched on catalogues or collections yet, but we can look at these later. Basically, you will be starting off by importing into the default catalogue.
Remember, Lightroom does not change your original files at all. It creates a database that stores information about each of your image files.
I think it is important to take things in small steps so that is enough for now - try importing a small number of files and let's take it from there.