You can setup the computer with a local account and create a dummy account called 'User' just to reach the desktop and let the user create any additional accounts if needed.
One of the easiest ways to ensure it defaults to a Local account is to temporarily disconnect from the Internet.
Windows 10 setup only provides the option to set up a Microsoft Account if you are connected to the Internet. If you are not connected to one, setup will default to a local account.
Local Account – this account works like credentials used to log onto Windows 7 and earlier versions of Windows. A local account doesn’t include the modern benefits of Windows 10, such as PC Syncing, the ability to download apps from the Windows Store and two-factor authentication. A local account also requires setting up a hint in case you forget your password.
Microsoft Account – this type of account uses a Microsoft email address linked with your Microsoft account. Normally, this email address would use the hotmail.com, live.com, msn.com or outlook.com domains. You can set up Windows 10 with a yahoo.com, gmail.com or icloud.com address, just make sure that email address is associated with a Microsoft account.