Sketching this in isometric

I'm at present figuring out a reasonably easy design in isometric however since I'm a newbie I simply can't get it proper. Might anybody assist me visualize the way it'll look with a fast sketch? I've been struggling for the higher a part of 2-3 hour, with no ai to assist me with this.

I don’t know what does making nook b the bottom level of the drawing means nor the right way to visualize this and the right way to resolve which aspect is entrance of aspect as a result of the ebook I'm following doesn't even inform us about it. Might anybody assist? Thanks prematurely!