@Baytowerman  The default Windows partition layout is fine.  If you want to customize it for something like having a separate Data partition apart from your OS partition, which can be convenient especially if you perform images backups and might want to be able to roll back your OS without rolling back your data, you can do that, but you don't need to do anything special just because of the RAID 1.  Are you familiar with how to create a RAID 1 virtual disk using the firmware-level Intel Rapid Storage Management application?  I tend to prefer to set that up before installing an OS, and at least in the past that was required, although it does seem that newer Intel Rapid Storage applications that you can run within Windows can perform an in-place migration of a single-disk Windows installation over to a RAID 1 setup that you'd define within Windows.

If the system came from the factory with a Windows 10 license, then you shouldn't have any activation issues even after changing drives and even if you choose not to use a Microsoft account for your Windows logon.

I personally would go with regular Microsoft Win10 install media rather than Dell's though.  But that's a personal preference.