Yes, you must have a verified account in order to participate in the contests. It'll take just about a couple of minutes :) Which will further allow you to make submission,Contest,Participate on live all things on the community and unlock a whole lot of other features.
All the members of the community are sent a notification informing about new contests. We also us send the users, by default, invitation emails for upcoming contests. You can, of course, prompt-out of these emails in the settings page of your account, whenever you want.
Users are given specific titles as rewards after they reach certain milestones in ratings: