Hello Theokus, I think you are entering the realm of mastering here. There are volumes on this topic. At the very least mastering involves getting all of the songs on an album to sound like they belong together as far as EQ and apparent volume.
Depending on your version Sonar comes with several limiters and compressors. The art is learning how to use them. You can normalize tracks but that will only bring up the volume of each track to max level based on each tracks highest peak. I think what you're after is apparent volume which involves using a compressor and/or limiter.
My advice is to do a little research and get your head around the basics of compressors and limiters. It may seem daunting at first but it's really not very complicated. You'll be glad you did.
Rocky