Azure Portal is a GUI that lets users manage their Azure subscription. In order to login to Azure Portal, the only requirement is a valid Microsoft account i.e. username and password which can be created for free.
Azure Portal Menu
Azure Portal Menu provides an easy way to navigate the various features of Azure. It can be docked or floating.
Azure Home: This is the landing page for new users of Azure. It shows a lot of userful information such as resources and guides on optimizing Azure subscription, a list of most recently visites resources etc.
Azure Dashboard: This feature of Azure portal provides a way to focus on the high importance, high priority stuff. The Azure Dashboard is user customizable. Azure portal also allows users to create their own dashboards and share it with other users within the organization.
Besides these, Azure provides a Quickstart center to get users up to speed with the Azure portal interface. There is also a feature called global search to get to what you are after, quickly.
While most users will have to pay for any resources that they provision on Azure, Microsoft currently provides a 12 month $100 credit for educators and students.