You can choose what information to collect from ticket purchasers. This setting is found in the Dashboard >> Tickets >> Information Collection.
We require first name, last name, and email address. You can show or require other fields as needed. Setting the password field to required means that an account will be generated. However, most events don't need to require passwords. Registrants are always able to go back to the event website and resend their tickets if needed.
You may also want to collect information from each ticket holder (so if someone buys four tickets for four people, you require them to fill out information for each person). This could be important if you are holding an event for which you need to know which attendees are minors, for example. Note that you will not be able to collect the email addresses of minors.