You'll never find a complete and easy answer to your questions, so much of the story has been filtered, contaminated, and altered that it is a challenge to understand it clearly. My only advice for you to read the contemporary letters, papers, reports and orders; coupled with later memoirs as those who were there to get a good outline of what was happening.
Pick a simple fact taught in public schools about the Civil War; one that is regurgitated over and over in the public media. Then do your own research on it from every angle using my suggested resources and I guarantee you'll get a slightly, if not completely, different answer than is being promoted. It is an eye opener to how many different stories you'll find on a Civil War subject.
You'll have to come up with your own answers and not simply rely, totally, on the information others are telling you. If you want to know who started the war, I have my evidences and information, through years of research, that do not follow the norm.