I'm new and have some questions before buying materials!

Unless I am missing something, the kit in the link is just a display, not a touchscreen.

The simplest wireless link would be a wireless UART or wireless RS232 link. It will look like a serial port on the PC and you can communicate via Serial.read()/Serial.write() on Arduino. It can be done with Bluetooth or WiFi, but it will require a little more knowledge on both ends (Arduino and PC).

Steve