Probably the best way forward for you is to download the free Kontakt Player.
Once installed on your computer you can select from the 50 instruments that come with it and learn the basics. You can tweak these particular instruments and change setting and save to use again and they don’t time out after 15 minutes.
You can also load Kontakt Player into any DAW that can host VST plugins (I assume Sonar can, but I don’t know for sure.)
Kontakt Player is essentially a demonstration device allowing you to trial Kontakt before you purchase it and while every instrument will load, the vast majority will time out after 15 minutes, after which you lose any settings and need to reload to continue to play.