If you're enough of a mechanic to at least access the battery you can put a charger on it for a few hours. Use, say, a 4 amp or less charger. 2 amps or less probably the safest. Then, hopefully it'll start and you can ride it to repair shop for further diagnosis. A good shop can test the battery under load condition to determine if it is good or needs replacement.
In my town there is a battery shop which deals with cars, atv's, golf carts, etc. They tested my battery in this way and determined it was fine. They asked me to rev engine while tester was connected and were able to tell me that it was not receiving an adequate charge at idle speed. I simply turned my idle speed screw to adjust it and problem solved. They did not charge me for the test.
I would call around and see who will do this test for you and also ask if they can get you a battery if needed.
