As a complete beginner starting out with learning Unreal Engine and such, I don't have much experience. While I find it easy to come up with gameplay ideas and mechanics, and the story behind the game, one thing I find difficult to wrap my head around is the process of creating a level from scratch and making a layout that works well with the game. How does the brainstorming and planning process go? How clear of a vision does the level need to have and how does it take shape?

Have you tried making a level and then playtesting it?