Depending on the climate - in 50 to 60 degree weather a corn/sugar mix will kick off in about a week or less and make a sweet mash, merely pour your corn in, fill with water about 4 inches over the corn, let it soak for about a week. Once it soaks up it will be breaking down, add your sugar and stir it up. Go back and stir it once a day or two - no yeast needed.
You can add a teaspoon of baker yeast to 50# of corn and 50 pounds of sugar and kick it off faster, but you do not need it. Watch your bubbles - once it stops working it will stop bubbling and will spoil in days.
If you do not want to make that much - cut the 50#/50# down accordingly. I have feed domestic hogs this slop to fatten them up 14 days before slaughter - they eat it up.....
I have heard tales of some wrapping a 55gal barrel with hay and blankets in cold weather to help it kick off. Making a sweet mash is not hard and the resulting liquid is corn beer (sweet mash).
Do not cover the barrel tightly. A board over the top works fine and lets the gases escape. Expect a rotten beer smell from it that will attract horses, cows, pigs and other animals - including your local revenuers......
CAREFUL however you are skirting the law doing so, and could very easily be taken for making shine. In some states it is ILLEGAL to mix corn and sugar in a barrel.
I have seen soaked corn and diesel work VERY well. I have also seen a hole dug 2 foot deep, handfuls of corn with cherry jello powder thrown in and then covered up work very well.... Personally unless you live in the country - stay away from soaking corn and adding sugar to the mix - neighbors can get the wrong idea, and the BATF has zero tolerance for it. To many other proven hog getters to mix up then just corn/sugar.