I am extremely new to WordPress CSS, so I really don't know what I'm doing. So I'm having two problems:
1. I want to add a background image to my website (which is diybudgetgirl.com), which is easy to do. But I also want my content (sidebars, menu, footer, and body) to retain the white background color so it's easy to read. I got a background color to appear on most of it (I can't seem to get the subsidiary widget content at the bottom to do it), but I want the background to go all the way to the bottom (in the sidebars, it just stops where the widgets end) and I want all of the white parts to be connected to each other. I don't want them to be islands, I just want them all to be one white area, from the menu all the way down to the end of the footer. (If it's helpful, here and here are screenshots of what it looks like when I add the background. I took the background image down when it wasn't working. If you need me to put it back up, let me know and I will. I would just prefer not to if it's not necessary.)
2. I want to put my top menu and my social media icons at the top of the page, next to the header image. I can't figure out how to move the menu (and I will obviously be removing/combining some of the stuff IN the menu so it will actually fit). When I put the icons in the header widget, it pushes the header image up and puts the icons on bottom, which is not what I want. I want them to be at the very top, on the right.
How do I do all of that?
I (finally) have a child theme, but I don't know how to do customizations in it. Do I just copy the whole style.css code from the parent file?
Obviously, I am completely lost. I've done CSS outside of WordPress and it was so simple...but in WordPress it's like absolutely nothing is what it seems. So any help is greatly appreciated!