Using Mac to connect PlayStation 4 to VPN I am trying to set up my PlayStation to have VPN set up.

I have a Mac. I thought about buying a router, but it is too expensive, and I don't need a wireless setup. My Mac doesn't have LAN ports, so I cannot buy one Ethernet adapter as I need two lan ports to connect my Mac to Internet and the other to connect the Mac to PS4.

Is it possible to buy two ethernet adapters to make this work? Or is it better to just buy a cheap router that will support VPN?
It sounds like you need an inexpensive switch. Plug the router in to the switch and your PS4 and Mac into the switch. 


TP-Link 5 Port Fast Ethernet Switch | Desktop Ethernet Splitter | Ethernet Hub | Plug and Play | Fanless Quiet | Unmanaged (TL-SF1005D), White https://www.amazon.com/dp/B000FNFSPY


You could get faster networking in your building to go to gigabit speeds, but it’s unlikely your VPN or internet are faster than the switch I linked to. This won’t solve the VPN side, so ask that on a network site or once your physical network is working. 

I would not have your Mac relay traffic when network gear is so much faster and power efficient.