Hi yayitsdan,
first of all, I think that an IBM 5150 is definitely not an easy thing to model. Certainly not for a beginner. I know I could do it, but it would not be simple for me and I am not a beginner.
That being said, if you want to model this, by all means, go for it. It’s a great model.
Edge loops can become messy, but they’re probably the easiest way in this case. (For a beginner, and I don’t mean that denigrating in any way!)
I’d say, keep doing it the way you are going (and should you get stuck, maybe switch to something a little bit easier).
It won’t be the best topology (edge loops going all the way around your model), but a hell of a model anyway. And it will probably inspire you to learn a bit more about topology and modelling before going on.
I know it’s tempting, you want to make something amazing immediately, but it just takes time; there is a lot to learn.
Sorry I can’t just tell you in a few words how to do this.