The wires and connector beneath the seat are for diagnostics, so leave them alone.
An aux light(s) should be powered off a relay in this or most any vehicle. And you will also want to add other items over time, such as heated jacket, cell phone power, aux horn (another relay if a high amperage one), etc. That's why most owners will add a fuse block such as the Fuzeblocks FZ1 shown below or Eastern Beaver PC-8. That's one set of wires to the battery and an easy place to run all your accessories from. I went with the FZ1 because simply by moving the fuse you can change power source to/from switched or always-on. The easiest place to tell the fuse block when the bike is running is to splice into the cigarette wire, which is at the top of this compartment.
Fuzeblocks:
https://www.advdesigns.com/fuzeblock.html?gclid=CjwKCAiAyMHhBRBIEiwAkGN6fAfE9P6GEYcvYpGIe-E2uTCJQL9qACKOx562_nbLpyWh28co2K9UZRoCUtQQAvD_BwE
As for size of fuse, it's always a minimum of 3 to 5 times the electrical load. If you are adding a 60W light, the bike has a 12V system, so:
3 x (60/12) = Minimum fuze
3 x 5 = 15A
The diagram below shows how to hook it all up. Pin 86 would connect to the cigarette lighter wire and pin 30 would connect to the Fuzeblock.
Don't forget to consider wire size. Most of our routings are well under 6' so you can get away with 16 GA on an intermittent circuit like a light, but ought to use 14 GA. The trigger wire and pin 85 ground wires can be 18 GA or almost anything, as they carry very little current.