As I said, there are many different ways to do any of this. I'm sure there are articles with photos on this forum that show how some people skin them, probably different to the way I do it. Also, you don't need a plucker to pluck them, many pluck by hand. That kind of depends on how many you are doing. If you are doing several a plucker is handy. If just one or two it may not be worth setting it up and cleaning it after.
Many people leave the carcass whole, I cut mine into serving pieces and use the carcass to make broth. Some people only use the breasts, thighs, and drumstick and may cut those away without eviscerating. One of your decisions is how do you want to prepare the meat.
The basic tools you need to skin them are a sharp knife and a surface to work on. I find running to be really useful. I use poultry shears to make certain cuts where cartilage or bones are involved to keep the knife sharp.
First I remove the feet. The head is already gone. After I remove the feet I make a cut across the belly big enough to get my fingers in, then I start pulling the skin off by tearing it. One hand pulls toward the head, the other toward the tail. With relatively young birds the skin pulls off pretty easily. As they go through puberty the cockerel's hormones cause connective tissue to grow that makes skinning harder. This connective tissue helps connect the inside of the skin to the body as well as joints to each other. I find this starts becoming a factor with cockerels around 16 to 20 weeks of age. An old rooster can turn you off from ever skinning again. I sometimes use a knife to cut connective tissue.
The wings are a problem. Some people just cut parts of the wings off and don't bother. There are three sections of the wings. The first part next to the body isn't usually too bad. The second part that has the flight feathers are a pain. I use a knife to start the tear to make it easier to pull that bit off (you should see what I mean when you try it). Sometimes with an older bird I wind up cutting that entire flight feather connection off. I don't bother with the wing tip and just cut it off. It's not worth it to me.
Another hard part can be the legs, especially the bottom of the drumstick. I sometimes split the skin down at the bottom to make it easier to pull it off. Having the feet cut off helps too. Another potential hard spot is the top of the back, especially on the older birds. For some reason the skin likes to stick to the backbone. I sometimes use a sharp knife to help peel that off. Your young flexible strong hands may find some of this easier that somebody with old arthritic hands.
That's basically it for skinning. My next step if to eviscerate the bird. There are different ways to do that, a lot depending on whether you want a whole carcass or pieces and what pieces.
As for what to do after you need to age it until rigor mortis passes. That could be two days or more. You want the joints to move freely and the meat to be really limber. Some people age it in the fridge, others in an ice chest. It needs to stay cold so bacteria can't grow. You are dealing with raw meat so sanitation is important. After that, you freeze it or cook it.
