I haven't ridden my motorcycle for a few months due to an minor accident, but my motorcycle won't start up. Sounds like the battery is dead or the engine is giving up (i'm pretty sure it's the batteries).
You do realize theres literally hundreds of different bikes that the "ZX" moniker covers, right? Need a little more info then that! The most common place to find batteries on Ninjas is at the front of the undertray, right under the seat. Just start unscrewin' stuff til' you find it!