Here are my thoughts to your questions/problems
1 Forget about getting the "perfect" picture, at least for the time being. For the average photographer it might take your entire lifetime, if you are lucky. For the gifted, you might make it in 20-30 years to make that "perfect" picture.
2 From your second post, it appears that your basic issue is that of exposure.
It is fine to know how your camera function. But to get your exposure right, you must understand light. Yes, today's cameras have wonderful computers built-in. But the computer is doing the work, not you. So you should learn about light and how it impacts on the sensor.
For the time being, forget such things like flash. Just try to understand available light. Flash is another discipline.
There are books on such a topic. One is called "perfect exposure' by Peterson ( I think)
Good luck!