I am not from Laminar Research; just a flight simmer from down under running X-Plane through a windows platform.
Based on what you were told, contact the retailer and ask how to run the software when you have no Disc drives. Depending on where you live I am of the opinion you have been "dudded" or "sold a pup" in relation to the software.
Others have raised the same problem as yours in this forum. How did they solve it? I don't know. I read all of the forum questions and answers and cannot remember seeing a solution. You may need to scroll back through a number of pages to find a possible solution.
One solution may be to purchase an external disc drive and connect via a USB connection.
An alternative way I know of to run X-Plane, in your situation, is to download the digital version directly from Laminar Research. With the digital version you are given a password key to activate the software. With the disc version you will need to have disc 1 inserted all the time when running the software.
In relation to what you intend to use X-Plane for, you need to consider your screen size. If your Macbook is any smaller than 17 inch you will have trouble seeing anything ( stated in earlier comments in this forum). Ideally a 27 screen will start to give you something decent to look at. Stay with a 1920 x 1080 configuration. X-Plane will not run very well with a 4K screen Everything will be too small to read ( comments in this forum)
X-plane is very resource hungry on the CPU and GPU generating a considerable amount of heat. Good internal cooling is required. You need to consider this as well.
Hope you are able to find a solution and welcome to X-Plane.