Height of the header / logo size

Hi! Ive a slight problem with my site.. I wish I could make the header a little higher, because my logo (name) is just too small ?? How would I be able to add

a. either a pagewide (not full width) picture / headline?
or
b. make the logo bigger/higher on the left side?

I hope you understand what I mean..
link https://www.ghanavisits.com