The personal edition has lot's of script to automatically installed Pega on Windows.
IMHO, it is too much to try to reverse engineer these script to adapt then to MAC.
I would suggest a different approach. If you don't have a Windows machine, download a free virtual machine and install Pega there. Microsoft has free virtual machine which you can run for 3 month I think.
This will get you started.
Then, afterward, Pega personal edition is essentially composed of 2 components: tomcat and postgress database.
You could potentialy later on install Postgress (on its own) on your Mac and export Pega schema from your virtual machine to your Mac.
For Tomcat, you can copy/paste it from Windows to your Mac (I know I'm shocking some people there), then you will have change some setting (in particular the context.xml) file.
I'm not saying this will be easy, I'm sure you will learn a lot and I expect this is doable.
Yes,You can install pega 7.4 in mac. For this you must have the disc image in ova format. Install VMware Fusion in your mac and import the ova disc image in the vm. After imported successfully go to system preferences option under top left apple symbol and select security and privacy option and enable the allow checkbox.Now you can run the VM and use Pega7.4 https://www.youtube.com/watch?v=EMmRkr1uGVw