You say the bike was sitting for 15 years?
The bike will start with a dead battery. The battery is there to run the accessories. The battery will charge up once you get the bike stated But I bet you need a new battery. When you turn the motor over the headlight should come to life with the Stator spinning.
There is one main fuse. But the bike will start with a blown Fuse and the head light and tail light will still work cause of the stator. The battery is needed for the horn, brake light, turn signals and to keep the lights bright when your stopped
First Check and see if your head light comes to life when you turn over the motor. If not check and clean up the battery ground. If the head light comes to life when ya turned over the motor. Check spark plug wire to coil and that the wires to the coil are plugged in also check all other starting system plugs Look for any damaged or loose wires.
I see your bike has a rear mounted stop light switch. I have heard that switch must be plugged in because there is a hidden ground for the starting system.
Before trouble shooting any farther, If you don't have spark replace the CDI with a new one. The CDI is under the tank