Optional Sidebar

Hi, I have a couple questions on how to make changes to my current theme. I am currently using Adventurous Pro for my website: www.ourdogjourney.com 1. How can I reduce the padding around each widget within the right-optional sidebar? Right now I feel like there is too much space between each widget. 2. How can I reduce the padding that is at the bottom of my social media bar at the top of my site? (The space between my main header and the social icons). 3. Is there a way I can add a line or divider between my page content on the left and my optional right sidebar? That's all for now. Thanks!