How long does it take?
Shredded and in a tumbler with a lot of work and effort can be done within 6 weeks, is what I hear.
Dump it in a pile and never touch it. A year.
I dump mine in a pile and when I need some, I scrape off the outsides to get at the dark, rich gold in the middle (finished compost). I have 2 pallet bins started and will start a third. In theory, the first bin is collection, second bin is active and third bin is finished and ready for use. A lot of people screen out the big stuff and toss it back into the piles.
Decide how much effort you want to expend (save the gym membership!) and pick a method. It is also determined by time available (do you have kids?), how big your yard is and how much organic waste you generate or haul in.
To make compost quickly, 2 parts carbon (shavings, wood chip, newspaper, cardboard, dried leaves) to one part nitrogen rich (green leaves, chicken poop, manure). Shredded is quicker. Water and mix. Some people actively turn compost piles - tumblers and once a week bin swapping - and some put it in a pile a deal with it when they get around to it.
With 7 chickens, you really aren't going to be generating much. With a small yard, you don't need much. I'd suggest making a bin in the corner and not worry about it. The bin can be as simple as an old trash can with the bottom out and holes drilled in the side for aeration to a 3' circle of fencing. As it rains, the compost tea that comes out will make that the most green section of the yard. At one time I had a fence circle in the middle of the garden. Worked well.
Be warned, fresh kitchen waste may attract rodents. If you have a rodent problem now, you'll want a vault. Bury waste in the middle of the pile.
Cheers!