Using a wiki is often possible without creating an account (this depends on the security preferences).
However, using the wiki with an account is easier and better, because you can:
set a temporal bookmark on RecentChanges.
To create an account, use the link you can create one now on login page. Then you will have to enter:
a name (it is a good idea to use FirstnameLastname).
Then click on Create Profile.
The account will be created and you can log in to the wiki using your user name and password.
You are logged in if you see the user name in the navigation area.