Hi there.
Since 2004 we got whole new material system, all with pbr. Then we have lightmass ie static lighting system. And blueprints which is really great visual script for making projets and games.
There are plenty of tutorials, basic editor navigation is still there. So create some old style map with CSG, then light it and texture. When you get hold on that, import some of your arch vis projects over.
And i think this will be good start for you: UE4: Workflow Tutorial - How I Created "The Corridor" Environment in 10 Hours with Unreal Engine 4 - YouTube