On my Sportsman the battery shutoff switch was mounted on the left side (drivers side) of the tongues inside face close to where the battery is located.
Once you get to the CG and connected to power everything should work as advertised.
The two must-have adapters are the 30A-20A adapter as you just found out and the 50A-30A adapter. You may carry the 50-30 with you for a few years and not need it but the day you realize you need in becomes worth its weight in gold.
It's always fun showing the new guy around his new toy so come back with your questions :)
