Cerauno CSS Help

Hi, I need some help adjusting the css on my cerauno theme and would be so grateful if someone could help me! So here is what I’m trying to do:

1. Adjust the header image so that it fits in the area there. Right now the image seems to be blown up and I just don’t know how to fix it. I’ve resized the image a million times and it blows it up regardless. If there was someway to get right of the lines restricting the header image altogether that would good too.

2. Instead of having just a portion of the featured image/content in a post shown, I’d like all the images and content shown on the home page.

Are either of these things possible to do? Thanks!