If you're going to have the computer onboard with the robot, you can benefit from a direct USB connection.

However, if the robot and the computer are in the same room, then you'd need to put the EZ-B in client mode and connect it to the same WiFi network as the PC. You won't need two network adapters for that.

EZ-Robot has a good tutorial (starring yours truly) for the EZ-B Wifi modes here: https://synthiam.com/Community/Tutorials/15?courseId=4

So if I were to use the USB method to connect to the EZB. Could I still VNC into the mini PC without using the internet? Maybe turn the mini PC into a AP to connect?

You will need an internet connection if your robot is outside of WiFi range for a direct connection.

However, if you’re pc won’t have a screen and that’s the reason for vnc, then yah all you need to do is put the pc in ap mode.

DJ, would this cable work to establish a USB connection?

https://www.amazon.com/JBtek-WINDOWS-Supported-Raspberry-Programming/dp/B00QT7LQ88/ref=mp_s_a_1_3?crid=2IA3E5MPOAYVX&keywords=ttl+to+usb&qid=1554138239&s=gateway&sprefix=ttl+to+us&sr=8-3

If you're running Windows 8. Look at the supported operating system when you're purchasing hardware. Here's EZ-Robot's tutorial for USB adapters: https://synthiam.com/Community/Tutorials/76?courseId=4