depending on the version you have...Sonar has a series of instructional videos that explain the basics. They are on the cake website.
All the DAW's on the market have a learning curve. Start with the basics so you have a foundation to build on.
Everything you mentioned is just a click or two from the start screen. Adding new tracks to do the voice over.... from the top menu bar... Insert audio track....
please slow down and watch the video's on this site....and there is a very comprehensive user manual there for you to use. Get the basics and it will be so much easier to use properly.