hmmm...so leaving the lid off would be a good idea. Thanks for the reply. Guess I will have to leave a light on as well.
That's funny! No, you don't need to leave a light on. You want it moist, but not wet. If it's just a little too moist, leaving the lid off will work.
The mold and mushrooms are normal in organic soil. Go by smell. If it smells nasty, it's too wet and went anaerobic. Still be ok, you just need to dump it out and let it air out. Wheelbarrow, kiddie wading pool, whatever you have. Turn/mix with a shovel every day or 2. A few days in the sun will set it right, don't toss it.
I use the same or similar cans, 32 gallons with lid. $10 from HD. Drill a few holes in the bottom for any excess water to run out if you get your mix a little too wet and a bit of air. Not like drainage holes in a pot, but enough where it won't hold water. I do ~10-12 1/8" or so holes.
You'll be fine.
Wet