You do have options. Most of the rail CAD programs like SCARM or RR modeller run on windows. With the MAC, there are ways to run windows software,bootcamp, parallels and there is another program whose name escapes me (pretty easy to look that up on the web). It isn't necessarily hard to run windows on a mac, but it does take setup work and I believe boot camp and parallels will require you to also purchase a copy of windows 10.
I use a mac and I use railmodeller pro and I found it to be easy to use and met my needs. I tried Scarm and RR track and honestly had trouble using them (a lot of that is on me, graphic design programs are not something I do well with), I didn't find them the least bit intuitive. Given my needs were simple (no grades, I didn't do any 3d modelling, etc) it is possible railmodeller would not work as well as Scarm or RR track software.
