If your question is about monetization and why you got denied. Typically, they will tell you why you were rejected, things like "reused content" or "copyright violations", etc. If you were uploading content that did not belong to you, I would understand why they would deny you. If you purchase music through a service like iTunes, it does not grant you license to use it in online videos. It's a different type of license you would be paying for. If you purchased a membership to someplace like epidemic sound or soundstripe, you have to make sure to follow their rules for registering your channel with their service so that if they catch the music in their content ID system you will get the violation flag removed if you are properly registered or you contact them to release claim. I'm not sure why you got declined, but I think you have the reason why. All I can offer is advice to keep going and apply again once you meet the requirements and realize that while adsense is always great, it's certainly not the only way to make money online.