Step 1 - Go into the "Forms-Tab" within your account & select "Create Form"
This is also where you find all the previous forms created.
Step 2 - Create a new form or use an existing one
Step 3 - New form
Complete all the required information, and ensure that you ask the user for the required information that will allow you to share the prize with them!
Once you've included all the necessary fields, you can set the form live & start assigning the winners.