OK, Komplete feels complicated until you get used to VSTs, all the types of VSTs, Windows file structures, samples, etc.
First, finding stuff. Native Access is your frenemey. Fire up Native Access (the tool that installs Komplete) and click on the little silhouette in top right corner. Under there, you will find “Preferences”. Under Preferences, you will find the locations of Download, Application, Content, VST 64, and VST 32. These directories are where Komplete/Kontakt are sprayed all over your disk drive(s). Your Libraries are under the Content Location.
You have to tell Cantabile (C3) where your VSTs are, and you have to tell each program where it’s Content (Sample libraries, Resources, etc.) are located. With C3, look under Tools-> Options -> File Locations. With Kontakt, you have to use the Browser/Files/Database locations. When you start Kontakt and load a VST, it will look for its resources. If it can’t find them, it will popup a files box for you to find them. There are a number of ramifications to this. Until you save a Kontakt configuration (in one of C3’s Racks) you will have to do this every time (there are exceptions, but it is a pain).
Pro tip: Create a directory (hopefully on a secondary drive) called \VST64 and one called \Content. All of my VST’s are in F:\VST64 and all of their content is on F:\Content on all of my 3 machines (C3-Primary, C3-Backup, Studio). I don’t use VST32, they are mainly for if you’re hooked on a legacy VST that doesn’t support VST64 memory model. You may also need to create x:\Downloads as a spot not on C:\ drive for downloading Komplete install modules. Komplete can fill up a drive with install modules.
This should get you started.