This is a SketchUp drawing. The free downloadable version works.
BTW for those without the software, the design has the outer skin with some detail eg door, windows; the trailer in high detail eg wheels, C-channel cross members, tongue detail. The inside has little detail, so hard to determine things like fridge placement, etc.
I think you need a little more on the inside detail to see how things will actually fit. Like the fridge, what are anticipated dimensions? In my planing, I have a range of possible and have created a space for the expected unit. The same thing for the foot well given the current placement of the trailer rails/cross units/tongue supports.
Most people do not design all the details like how exactly will the sides attach to the bottom; details on the hatch and edge water barriers (if you had a hatch ), door installation eg hinges, trim, window; how the inner, outer roof will be joined to the walls and spars; what to do when working with materials that have to be spliced together to get the correct size. One really needs to work on this at some point.
Other things to include : cabinets (currently none?), what electrical system you will have and where will it be contained, water system (?), propane, solar. Many people leave wiring pathways to a more ad hoc solution -- although planning is always good.
Generally the more planning, the more likely you are going to do/remember to do everything in the "best" order.
Scottish Terrier Fancier