Note: The RD Web Access role requires Desktop Experience; In Server 2016 you can’t change between core and desktop anymore.
First of all, I have made a script that will install and configure all roles and tools.
It installs the management tools on the server which the script runs on (from this server you can manage the core RDS environment).
Then it will ask on what servers which roles needs to be installed.
Find it on Technet
After everything is installed, add the servers to server manager on the management server.
However already installed and configured, you need to add the license server and RD Gateway to the farm.
It is already connected to the Connection Broken, but are not automatically detected by Server Manager.
Afterwards you should use Server Manager to add certificates to the RD Access Roles.
I would use a Wildcard certificate for RD Gateway and RD Web Access, since they are accessed over the internet.
Certificates for the broker role can be issues by your own CA, or if you use a public domain name in your internal domain (example corp.contoso.com), I would request an additional wildcard certificate for your internal domain.
The first part of the installation can be accomplished by following the steps in the RDS Farm setup script, the second part you’ll need to do using Server Manager.