2016 is the year I plan on learning Unreal Engine 4 from start to finish, the end goal having a small playable map by the end of this year. So far i have learned a tremendous amount from Alex from http://www.worldofleveldesign.com. I still have some tutorials by him I want to finish before this month is up. Currently my next move for next month is learning a 3D modeling program, most likely blender, so i can make my own static meshes, doors, windows, walls, etc. In March I plan on coming back to UE4 an focus on Blue Scripting so I can make flickering lights and open doors, etc. I know I want to be a level designer and that covers a broad area. My head is spinning right now and I’m seeking guidance from those who have walked in my shoes.
At the point you’re at the only guidance you need is to immerse yourself in it. Don’t take a break from UE4 to learn Blender, learn them consecutively. Model a door in Blender, export it to UE4 and see what it looks like. Make it open and close using blue-prints. Follow tutorials. Download free/tutorial content others have done and play with it - break it - learn from them. Challenge yourself until this stuff becomes second nature.
Yeah I think going along the lines of what Moo-Juice has said above is a good idea. If you really want to know the unreal development tools well enough, just dive right in and fully immerse yourself with everything. Dont worry about modelling in Blender yet, just focus on understanding what can be achieved with the engine.
The is a vast array of free assets online which you can use as placeholders for the time being, that way you can learn the editor and essentially have the ‘small playable map’ just without your bespoke made assets.