SQL Lab Connecting 2 databases 

Over the last few days I have been working on a few labs that cover a variety of disciplines.
I have a lab with two Windows Server 2019 (Standard Edition, and Datacenter). I am using one server as the Domain Controller, DNS, and DHCP.
Both servers are running SQL. This server is also running Microsoft SQL Server 2019 as the primary SQL server. All running on VMware.
So I set out three main goals to keep in mind.
The main purpose of the lab was to get more familiar establishing a server to run a SQL database.
I wanted to learn to link two servers running the same database using Active Directory authentication.
I wanted a better idea of database availability such as Always On Availability Group, Replica, Databases, and Listener.
After 3 days of tinking around I just discovered why I was able to link the two server in an "Always On" configuration on one server but not the other. Turns out, you can't have a Domain Controller server host the "Always On". It can participate in Availability Groups but not host them.
This so far has been a fantastic lab and a great learning journey. No doubt that running a database server nowdays on the cloud has tremendous advantages, but with this kind of set up a database could be in both places. Thanks to products like Azure and AWS SQL Data Sync you can now have a hybrid deployment allowing to place the data closer to the edge.
I don't mind sharing the journey. I hope that it motivates others to get in the lab and tinker.