I've been using the free SketchUp Make2017 since it came out, and prior versions before that. The new free version only works when connected to the web, something I didn't like, and has a poor interface IMO. You can download Make2017 from the web, for free, but it takes a little looking around since Trimble no longer supports the product. It works just fine though, so no support is needed. There's an add-on extension called Cutlist that will create a cut list of every part you identify and also lay out the parts on your lumber and plywood stock, too.
Some folks create incredibly realistic renderings with it, I think our member FS7 has shown some. I never learned how.
SketchUp can be used in 2D, but I don't see why one would. Using it in 3D allows me to build a piece of furniture, etc, virtually, with as much detail as I want. I use it for just about everything I build. I also can import the parts into my CNC software for cutting on my CNC desired.
Here's a model I did for a table I recently built.
John