There are a lot of guides out there for Microsoft Intune, this one is going to be focused at Windows Management primarily around Azure AD Join, replacing much of the on-premise functionality to provide a Modern approach to Windows Management.
I always start at the Windows Enrollment you can find this section under Devices > Device enrollment > Enroll devices > Windows enrollment. This section of the Endpoint Manager portal connects to other sections around the Azure Resource Manager Portal like Automatic Enrollment which will take you to the Mobility section in Azure Active Directory.