I've finally opened up Unreal and started blocking out the general structure and landscape of my environment. The landscape itself is pretty non-specific, but I mainly focused on getting the cabin in scale. I used the preset third person character mesh to measure everything, and right now I've got the general shape locked down.
I'm still using presets just to figure out the positioning of everything, but my goal for the rest of the day is to play with particles and learn how to create a slightly more believable water system.