Firstly, welcome to the game & the forum! Great to have you with us!
If you wish to make a new account, then you first need to ensure any other accounts you have are inactivated - which you already seem to have done. Next, all you need to is log-out and register a new account, just like you did when you first joined.
If you ever wish to have an inactive account reactivated, post a request with a link to your party page on the
Reactivation Requests thread. But remember - you're only allowed one active account at a time.