I installed your theme and customized it like I wanted (almost everything is done) but just now I realised that I did not install child theme but rather main theme, and that I worked on that main theme whole time. Is there a way to install child theme and transport everything I have done from main theme?
You can now install the child theme and then the settings you made will automatically move to it. Except the code modifications you did. You need to move the code modifications manually.