I accidentally created a second account, (called HeneryVIII) while trying to log in. Not sure how to delete it, if that's even necessary.
Topic on User talk:Looney Toons
You won't get in trouble with anyone for having two accounts, although Miraheze does ask "Please only create accounts you intend to use."
If it really worries you, the Stewards can help - make the request here.
What Rob said. ATT's main issue with multiple accounts is when they're clearly created either by spammers or vandals, and that usually happens quickly because neither type is prone to patience and careful long-term planning. If we see several accounts with similar names being created in the span of an hour or so, that's when we are likely to be unhappy.