You can retrieve your old Twitter account by going to their homepage (www.twitter.com). Below the "password box" there is a text "Forgot it?" click on it and it will redirect you to the "Forgot your password" page. Put in your email address that you used or simply your username. If you want a new account, Simply create another email account and go to twitter's homepage(www.twitter.com). Fill in the necessary fields and your new Twitter account will be made.