Register it with DMV and get motorcycle license plates.
Perform a thorough bike inspection to help ensure that your motorcycle is in good working condition. An accredited motorcycle professional is recommended. If you want to perform the inspection yourself, the Motorcycle Safety Foundation has a checklist see http://msf-usa.org/
Get educated and ride safely. MSF suggests practice rides to get used to your new bike and research personal safety gear.
Get the right insurance coverage so that you and your bike are appropriately protected. Liability, collision, comprehensive, uninsured & underinsured motorists coverages, medical payments and guest medical should be discussed.