Child Themes – basic question

My apologies if this has been asked before. I looked around but didn’t find something that quite answered my question.

I’m new to wordpress (and to coding) and would like to use a child theme. I know the very basics of child themes but have two questions.

1) I am using the theme Sydney. Under appearance–>customize in my original Sydney theme I edited some photos, colors, etc. When I implemented my Child theme all these edits went away. Is there anyway for me easily update my child theme .css so that all those edits appear? I tried copying and pasting the existing parent theme into the child theme css but that didn’t work.

2) As I am not a strong coder yet, I have a hard time identifying what needs to be altered in the css file. For example, while on my home page I’d like to have my “services” box span the whole page and have zero padding. My problem is, I have no clue what code to put in my child theme css file to do that, is there a way for me to easily find what coding is related to the services section in the parent them so I can copy and paste it into the child them and alter as needed?

Thanks!!