I want to write a long novel and i have some ideas about how the plot should flow but i'm not sure where to begin, i don't know how to start off the adventure effectively. I know i want him to get kicked out of his hometown, but for what reason? Committing a crime? a false accusation of committing a crime? can anyone give me some suggestions?
I'd suggest that you just start writing. You may find that you started the story too early and can chop off some stuff from the front. Or you may find that you need to back up a bit. But now isn't the time to worry about the WHY. Just start with him leaving... on his horse, in his car, by foot... The WHY may become quite apparent to you later on.
I totally agree with @hippocampus Start writing what you already know, even if it's all from different stages. As you write, the answers to your questions will come when they are ready. Don't try to force them as this will come across in the story. You can always go back and edit as much as you want or need, you don't have to get everything right on the first draft, that's why we have the delete key! (this is also why I'm not a brain surgeon!)
Remember that you can start with him on the bus with his suitcase, and let the readers wonder why. The fact that you'll also be wondering why doesn't hurt anything.
