I’m brand spankin new to unreal. I have gone through the starter tutorial which was helpful, but in building the room, it was just a matter of placing a bunch of walls together to form the room. In my case I wanted to try to actually model a real world floor plan to import into unreal and navigate throughout it. I exported as an fbx from modo and was able to get the model imported, but when I place my actor within the room, it says bad side. I tried disabling collisions which seems to fix that problem, but that’s not really a solution because then as I “play” with the model, I can move through the walls. What is the normal workflow for getting an actor inside a room and making the walls work for collisions? Thanks.
You will have to use one of those ways to create a collision: 
The problem is that you modelled the entire room and exported it as a single mesh. When you imported that into unreal, it created a box collision around the entire mesh. Double click the model (to bring up the model editor), clear the collision model, and start adding in custom collisions.
edit: Since I had to do some work on my stuff, here is what I’m talking about:
This is what the default import should look like - mileage and model dependent of course.
://i.imgur/GtyzBfw.png
And here is a better version of collision so our player(s) can actually traverse the model:
://i.imgur/ByqvEce.png
Thank you both very much! The setting to “use complex collision as simple” worked great!