What’s gone wrong?
Most likely, the fuel in the carbs has dried out and, assuming you have a mechanical fuel pump, the engine hasn’t turned over fast enough or long enough to fill the carbs to let it start properly. Happens all the time in New England. It’s the climate.
Check for the kill switch, first. That was a good idea to check.
Also, put a battery charger on it to bring the battery up to full charge before you try starting it again - it might take a few seconds to catch when you try it again. Jumper cables would work, too, but let it charge for a couple of minutes at least before trying to start it.
If it were mine, I would remove the air cleaners so you can look down the carb throats. Then, get a teaspoon measuring spoon (or something close in size) and pour a teaspoonful (or thereabouts) of raw gasoline down each carb throat (just dump it in). Leave the air filters off for the moment.
Get right into the car and try starting it up. Just before you hit the key, pump the accelerator like 6 or 8 times and THEN hit the key. It will cough and puke a lot at first, but it should start and run a few revs to get fuel flowing from the fuel pump, then, most likely, it will die.
You may have to repeat the procedure a couple of times, but it should start, run poorly at first, then eventually smooth out. Keep playing with the throttle to keep it going until it will idle on its’ own, then it should be ok 👌.
If none of this works, something more serious is afoot, but if it has spark and has fuel in the carbs, even old fuel from last Fall, it should start. Sometimes it just takes a while at the first time in the Spring.
Good luck.