Pixhawk2 setup with AR7700 receiver

I’m just getting started learning how to work with my new Pixhawk2 autopilot to convert a fixed wing RC plane to an autonomous UAV, and I have found that online documentation for the Pixhawk2 is still quite lacking relative to its predecessor. I’m also new to both RC planes and to UAVs in general, so some of my questions might have obvious answers.

At this point, I’m expecting to use my Spektrum AR7700 receiver to provide PPM input to the Pixhawk, but I don’t have a cable that seems designed for the one-wire connection. I think I would need one that has a servo-style 3-pin female connector on both ends, but all I can find online are servo extension cables that are male-female. If I’m barking up the wrong tree and/or if someone can point me to a source for the right cable, I’ll be grateful.

Also, I need to be able to select the flight mode of the Pixhawk from my Spektrum DX6i transmitter. I believe a toggle switch can be used to select between two modes, but how can I access up to six? Since I’m new to programming RC transmitters as well, step by step instructions would be great.

The male to male cable you are after should be readily available from a local hobby shop if they support drones, eBay, or hobby king.
To begin with it is probably easiest to set up a 3 position switch to give you access to 3 flight modes.
Setting up a 2 switch mix can be a bit trickier to get to 6 flight modes but if you search YouTube I am sure you will find a tutorial or 2 to guide you through.