Lightroom has a workflow laid out in a "left to right" and "top to bottom" format.
The first thing you should notice is the name of their "modules" along the top.... e.g. "Library", "Develop", "Map", "Book", "Slideshow", "Print", and "Web".
You will likely spend most of your time in the "Library" and "Develop" modules.
"Library" is the asset management part. This is where you 'import' your photos from the camera or memory card and organize them. You can create "collections" which have names meaningful to you -- typically the name of the event or location, etc. ("Mary and Mike's Wedding" or "Grand Canyon Vacation", etc.) And then there are the folder which actually do correspond to real folders on your computer. Images are really stored in those folders. A collection is just the illusion of a folder managed by Lightroom. If I have a collection named "Street Photography" and I took photos this month and I take more photos next month, then the real photos will typically be organized into folders (on your computer's hard drive) named for the year, month, & date when they were shot. Since they were shot at different times they really are in different folders. But if I ask them to be added to my "Street Photography" collection then I'll see all the images in that collection -- regardless of where they really are on the disk.
You can create "smart collections" as well. Lightroom tags all sorts of meta-data with every image as well as keywords you can add and even ranking/scoring that you give your images (e.g. if you want to give an image 3 stars vs. 4 stars for example). So if i wanted to make a "smart collection" which includes all the 4 & 5 star photos that I took with my 70-200mm lens... I could actually create a "smart collection" based on those search conditions and everything that matches would automatically be displayed in that collection.
One more thing... if you use online services to publish images such as 500px or Flickr, etc. ... you can install plug-ins that handle the upload (publishing) of your images to those services. Those would be found in the "Library" module (you'd think they would be in the "web" module, but they're not.)
Ok -- so hopefully you get the idea that "library" is all about "managing" the organization of your images.
Next up is the "Develop" module. This is where you actually make adjustments to the images.
When you move to the Develop module, the most important thing to notice is that the right-side panel.
You'll see the histogram of the image on the top. But as you look down, notice the categories are things like "Basic" (basic adjustments are things like white balance, exposure, contrast, color saturation, etc.) , then you'll see "tone curve" below that, and so on. Adobe lays them out in this order because they think that most of the time if you plan on doing something with a category, you should do it in that order.
As an example... you should always set "white balance" before starting changing anything else because what balance will alter your perception of the color and saturation of an image. So if you mess with the color and saturation BEFORE you adjust white balance (and you could do that) you'll probably find the white balance just changed everything so much that you have to now revisit the color and saturation adjustments.
Watch a few intro videos to Lightroom and once you know the basic lay-of-the-land you'll probably start to catch on very quickly.
There are some nuances and hidden features that you wouldn't necessarily stumble onto if nobody told you there were there. For example, I had no idea that if you hold down the alt/option key on the keyboard WHILE adjusting a white point or black point slider, then the image will show you the pixels that are clipping based on your adjustment (it makes it very easy to quickly adjust the tonal range of an image. I call it a "hidden" feature because you might not think to hold an alt/option key while moving a slider. But now that I know about it, I use it all the time. This is why you should read books or watch tutorials even if you think you're comfortable using the tool.