I have been using Apple products since the mid 80s non-stop. When iTunes was created, I used one of my emails as the account name. When iCloud was invented, I created a username not knowing that down the line I would have 2 accounts to keep track of: one for my iTunes /Apple Store purchases and one for my iCloud based apps. After some Google searching, I found that it was possible to have all of these things in one account and lessen the amount of detail to keep track of in the Apple environment. It is somewhat tedious and stressful but there is a hackish way to combine accounts detailed at the 2 blog posts below. I will always have two accounts but if I can transfer everything to one account, I can then ignore the other account as I don’t think it is possible or wise to delete it.
Below are links to very useful blog posts on fixing the aforementioned multiple Apple ID account issues: