What can I say but the Reference Guide, tutorials, Help files, Youtube-videos etc. are there for a reason...:o) SONAR sure isn't a piece of cake. The Reference guide alone is about 1800 pages.
Spend a few days just studying the basics, step by step. Read one chapter about one feature so many times that you get the idea.
When you bump into something (and you surely will :o) that is explained in a manner you simply can't understand, you'll get help here, for sure.