Hi,
Manual mode is a great mode to use, but you need to understand the basic principles of photography (particularly the exposure triangle) in order to do so.
You say that you don't really know why you used those settings and that you write down settings you like to use in the future. The settings for shutter speed, aperture and ISO are all interrelated and vary according to the light, as well as what you want to achieve in the image as they also alter the way the image looks. The settings that produce a beautiful image in one case may produce a horrible mess the next time you shoot, because the light is different.
You say exposure compensation was zero, yet EC doesn't operate in manual mode so would always, in effect, be zero.
The exposure triangle, I mentioned earlier, is how you control the exposure. You balance the three settings (shutter speed, ISO and aperture) to allow just the right amount of light to record on the sensor. Too little light and the image will be dark, too much light and it will be very bright (as your examples).
ISO controls how sensitive the sensor is (how much light it needs). The lower the number, the more light needs to reach the sensor to expose the image correctly.
Aperture controls the size of the hole the light comes in through. The bigger the hole (smaller number) the more light can reach the sensor.
Shutter speed controls how long the sensor can see the light that comes through the lens.
There is a rule of thumb for judging exposure by eye, we call "sunny 16". That means that at f/16, the exposure on a bright sunny day will be roughly 1/ISO. So at ISO 100 you would want 1/100th second shutter speed, at ISO 400 you would want 1/400th second etc.
Now the interaction between them comes into play. We assess exposure in terms of "stops", each stop being a doubling, or halving, of the light. ISO doubles its number for each full stop (100, 200, 400, 800 etc) , shutter speeds also, but as a fraction so 1/125th, 1/250th, 1/500th etc.. Apertures are different as they are expressed as a ratio of the size of the "hole" relative to the focal length of the lens. so a large aperture might be f/2 and a small aperture f/16. If we look at a 50 mm lens, f/2 would give an aperture ("hole") of 25mm diameter (50/2) and f/16 would give an aperture of slightly more than 3mm diameter (50/16). On a longer lens, the f numbers would remain the same, but the holes would be larger to compensate for the narrower field of view. So on a 160mm lens f/2 would now be 80mm diameter and f/16 would be 10mm diameter. Aperture stops still allow double / half the light but the math now means that the numbers are not straightforward. The stops being f/1.4, f/2, f/2.8, f/4, f/5.6, f/8, f/11, f/16 etc.
The exposure that is required is always a specific level, determined by how much light is on the scene you are photographing. However you can choose the settings you use, to create the effect you want in your image, so long as you find a compromise that balances the three values to give that set amount of exposure.
So, to look at your images and compare them to "sunny 16", we see you used ISO 100, so we need the equivalent of 1/100th second at f/16. You used 1/50th so the shutter was open twice as long than 1/100th of a second, letting in double the light. Your aperture was f/7.1, rather than f/16, which is 2 and a third stops larger, so let in more than four times as much light. Combine the two and you have let more than 8 times the amount of light hit the sensor, than you should have. That is why they are so bright and washed out.
If you had used ISO 100, 1/100th and f/16 you would have had a pretty good exposure. You could alter the settings, if you wish, so long as you keep the balance. So you could use a faster shutter speed to freeze movement better, maybe selecting 1/800th instead, but that lets in 3 stops less light than 1/100th as it is open for much less time. You balance this by opening the aperture to let more light through the lens, a 3 stop bigger opening would need f/5.6 instead of f/16.
Think of it like a bucket with a hole in it. in one second a certain amount of water will flow through the hole. If you make the hole twice the size, then it will only take 1/2 a second for the same amount of water to flow through.
Did you use the lightmeter on your camera at all, or just pick the three settings at random? I don't know your camera personally, but you should have a bar scale in the viewfinder that alters as you change these settings, as you let more light in (bigger aperture, longer shutter speed or raise ISO) it will move to the right. Change settings the other way and it will move to the left. When it is in the middle, the camera is telling you that it thinks the exposure is correct. I say "thinks" because camera meters are easily fooled by bright or dark areas in the scene, and you may need to compensate for those. If there are a lot of bright areas, you will probably need to bring the needle to the left and vice versa for dark areas. If you simply centre the needle all the time, there is no point using manual as that is just using the same exposure the camera would on automatic or Av/Tv etc. but doing it the hard way.
There is a lot more to using the camera than this, but I have just touched on why your images are the way they are. You may be better off using the semi-auto modes for now and reading up on exposure (as mentioned above, "Understanding Exposure" by Peterson is the one usually recommended) and controlling your camera. Just jumping in and taking full control of a complex piece of equipment when you don't understand what the controls actually do, is just making things way too hard. Use some of the automation at first and gradually take over more control yourself, as you learn more about the camera.
Having said that, I would suggest you stay away from the full-auto mode (AKA "green box") and don't allow the camera to select the focus points itself. Make sure that you know which point you are using and that it is on your subject.
