Are you familiar with I2C? If you aren’t you really are going to want to start by learning on something simpler, ideally. The details are all in the datasheets under the I2C section. All information in that interface appears to be communicated via I2C (which is a serial communication protocol). In FT6236.pdf some sample code appears in section 4.2, with additional information about the contents about specific control registers a little above. If you look at that and can’t understand what is going on I really would recommend trying I2C on a simpler device first as practice to get more comfortable.
Looks like the display portion (not the capacitive touch) is SPI controlled, as detailed in section 7 of HX8238-D.pdf
I would say similar things apply as with I2C. Try finding a smaller project if you aren’t familiar with the protocol. For SPI I might recommend connecting a microSD card to the Electron via SPI as a project to get you started. It’s moderately challenging to start out, but it’s still small in comparison to the display, I think.