Header white space above and below logo

My site is www.tanjacrouch.com using Catch Everest theme. I have uploaded a logo but I do not know how to do the following: 1. remove white space above and below the logo 2. ideally, I would like the logo to be about 70-80% of what it is now. I know little. I read through a post with similar question about white space but I could not even find where you find the code to add it... I went to the editor section but couldn't and found a header section but couldn't find mention of the lines referred to to know where and what to add. Thank you in advance for any and all help. ALSO, I can't get my side bar to show up. It's all set up but it doesn't show up on the site.