I would have thought being able to model directly over the image would have helped a lot and it’s a pretty basic workflow step. Why did you omit this here?
Exactly like Spikey said.
If there was a reference for each view (front, side, etc.) then your approach would certainly be the right way.
There are many things in Blender and 3d in general, that are not necessarily right or wrong, but a different approach.
If you are new to Blender, you may have seen other courses/tutorials using a different approach, keep in mind every technique can't be taught in one course, unless the course was hundreds of hours of video.