Keying is definitely not a simple discipline to master. It takes time, practice, and a lot of trial and error. Maybe start here:
But I would definitely start by using the Keylight plug in rather than the Color Range keyer.
Color range is a lousy keyer. I would use Keylight. To learn how to key you need to go through some tutorials.
From your screenshot it looks like you are just poking around in AE instead of following a procedure. I don't see Color Range keying in your ECP so I'm not sure how you are pulling the key.
Here's the normal way to try and pull that key using your effects:
I used an old shot that I used to use in classes I taught that is so poorly shot that it's almost impossible to pull a good key. With just a couple of clicks and Keylight I get much closer to an acceptable key.
When I'm pulling a key I like to put a bright color behind the key because it's easier to see the problems. In this case it's a bright red solid. It reveals the problems with the reflections on the bike and the seat much better than any other background would.
I would suggest that you type Keying or Keylight in the Search Help field at the top right corner of AE and follow some tutorials. If you really want to spend time learning Color Range key- a keyer that never worked very will unless the shot was nearly perfect then type Color Range in the search help field and look at a few of those tutorials.
BTW, when you are having problems with a layer and you need help it's very useful to select that layer or layers in the timeline, press the U key to reveal all modified properties, then make your screenshot so we can see what's going on. Collapsed layers and Effects don't give us any idea what you are doing.
Hmm will this help ?
Umm.... I thought of getting a mask of the original layer and just using that over the new layer where I used color keying and animate that on the time line
On the above one I thought I would just create a mask with the pen tool and just use that mask over the layer below so that the shoulder part will be fixed.
That footage is probably never going to key well with the color range keyer. I would abandon it in favor of Keylight. You should be applying your masks on the same layer you are keying.
You need to look at some tutorials on keying. Follow my advice and type keylight in the Search Help field to find several good references.