Once an account is created you will be given a username.
This will take the form: firstname.lastname.cc
cc is the 2 letter country code for your country of residence, usually the same as the last 2 letters of an email address.
You use your user name to log in, NOT your email.
You set your password when you register but if you forget it, you can use the Reset Password link on the Log in page, to create a new one.
In case this helps you remember, your password must be at least 8 characters long and have at least 1 upper case letter, 1 lowercase letter and 1 number in it.
Once you log in, you will see your Profile page, which displays your account information, food and mobility restrictions, flights, group members, events and purchases.
If you have an open cart with unpaid items in it, there will be a button to view it.
You will also have a blue My Account button on the menu, where you can display your profile , change your details and check your orders. emails etc.