When you're ready to read about fares out of CMB, read
this. Warning: there are 513 posts in that thread, so settle in for a lengthy read!
I'd suggest you focus first on your RTW routing, keeping in the back of your mind that fares ex-CMB are relatively affordable, but not trying to understand those nuances yet. You have a very steep learning curve ahead of you, and will get serious indigestion if you undertake everything at once.