OK well now comes the fun part. You must confirm all of your connections. Start with the battery, and after confirming the ground is good, move to the starter solenoid, then up the wiring harness to each electrical connection you can find. Unplug everything, scrape away corrosion if there is any, and plug it back in. Be sure to fully assess your main wiring junction. On most cruisers and older bikes, this is actually hidden inside the headlight. On newer bikes it will probably be somewhere around the neck of the bike. You may have to take off fairings or the tank to do all this, but be methodical and thorough.
This is what a typical starter solenoid looks like: