Hi, i hope this helps:
1st
just go to wp admin -> Pages and rename "Cart" into "Shopping Bag"
2nd, edit file:
wp-content/themes/StyleShop/style.css
now is defined as
#main-header {
padding: 90px 0 33px;
}90px is up, 33px is down, you can change this arguments to get what you want (set it to padding: 50px 0 0px;) if you would like to keep size of current logo