You have a couple of options within EventCreate if you're interested in sending save the date information and pre-registering interested guests.
CREATE TWO WEBSITES:
Set up your event site and choose Simple Registration. Then, once you collect the information, duplicate your website and create a new website for guests to purchase tickets. For this event, choose Ticketed Registration.
To have more than 1 event at a time, you will need to be on the Personal+ plan or higher. Here is more info on the features available by plan: eventcreate.com/pricing
USE ONE WEBSITE:
First, set up your event site and choose Simple Registration. You can send out an email and collect interest via Simple Registration.
Then, when tickets are available for sale, change your registration to Ticketed. If you use the same website, you will need to allow your guests to register more than once by using the same email address. To do this, go into your Event Dashboard, then go to Setup > Registration > Advanced and uncheck the box next to My Attendees Cannot Register More than Once.