Once you have logged into your organization's hackathon center, you'll be able to begin participating in hackathons.
Visit the Active hackathons section of your hackathon center or click on Hackathons within the side menu and you'll be able to view and register for hackathons that have not recently ended.
If you're interested in registering for the hackathon, simply click the blue Register button on the top of the hackathon page. If applicable, you may be prompted to respond to various hackathon registration questions and after inputting your response, click Complete registration — you are now registered for the hackathon.
Please note that if you did not mean to register for a hackathon, you can unregister by clicking Unregister on the right side of the hackathon page.