While I hate suggesting programs that substitute their price by building in Google telemetry, (like really, fuck off with that shit) Fusion 360 or a similar more advanced program would be better to learn CAD in, since it makes creating detailed parts that are required in a portable way easier. It's going to take a long time to learn Sketchup vs. Fusion. But for concepts like this it's fine.
Anyway! I like the design, it's kind of exotic. Kinda like an Atari Lynx? Hope you succeed with making a portable!