Here's everything you need to know about creating your form.
First, click the 'New Form' button in the menu on the left hand side when you are logged in to CreateForm.
A box will appear in the middle of the page with the option to name your form. This is just for your own reference so don't sweat about it too much.
It is here where you will choose your form shortcut URL, e.g. enter 'my-example' if you want your URL to be crea.tf/my-example. It will tell you if your desired URL is already in use or not.
When you're ready, hit 'Create'.
Your will now be taken to the form creation wizard.