Setting Up Server as Active Directory Domain Controller

Keeping it simple, select install Active Directory Domain Services and DNS Server, via Manage ---> Add Roles and Features.
After installation, promote your Windows server to a Domain Controller :
A Deployment Configuration Wizard screen will pop-up. This step is important to properly setting up active directory services! Select Add a new Forest to begin the configuration wizard:
Here you can see I've entered AD.testlab.home as my Root Domain Name
Here you can set levels if you plan on connecting other Windows Servers. For my purposes, I'll be keeping it at its default of Windows Server 2016
Set your DSRM password and store it safely. 
If you're setting this up in a test environment, you'll likely see the following warning pop-up. For our purposes, this is okay:
Click through Additional Options, Paths, and Review Options to get to the prerequisite checks:
Again, these warnings are okay for test environments. For production, you'll want to acknowledge them and make changes accordingly.
After installation, the server will need to restart, and you should now be able to log in as Domain Administrator, which should say AD/administrator:
Useful Tips:
If you're like me, you're using an evaluation copy of Windows and don't have any plans of purchasing a costly license anytime soon. To rearm the license and reset the count back to 180 days, run the following command in PowerShell:
slmgr -rearm