Okay, so here's the step by step of what I'm doing. If it's something simple I'm gonna feel like a moron.
- Go to NCsoft account management
- Click on "Use a Serial Code"
- I have the choice of entering a serial code or clicking on:

- I select the City of Heroes one because as I stated before, I have no idea
where my serial code is (It certainly hasn't been emailed).
- I'm magically whisked away to a page that states "To create your new
City of Heroes® account, choose an account name and password." One
of my options here is to use my NCsoft account name and password as
my CoH log in. I ecstatically click the "Create Game Account" Button
because who likes typing out a new username anyway?
- Aaaand we're taken full circle back to this:

I don't have this information.
Update: I tried purchasing the magic booster pack to see if it could do something like force my first serial code back into existence (Like, Oh you purchased the game and you're trying to add an upgrade to it, but you haven't registered the game yet, so do you wanna do that now?). But unfortunately all it really did was say "well, you can't add a booster to a game that isn't registered; so you gotta wait." Lame, I want to get out of this trial account and into the wonderful world of being able to talk back to people.