You could use images, but text would be better if it’s text.
I see the background image in the header is a gradient, that would be much slicker done with css rather than an image.
background: linear-gradient(#231F1F, #040100);
You can make adjustments using margins or padding.
padding: 10px /* gives equal padding all round */
padding: 10px 20px /* gives 10 at top and bottom and 20 on the sides */
padding: 10px 20px 30px 30px /* 10 top, 20 right, 30 bottom and left */
padding-top: 10px /* just alter the top (or W/E side) */
Same goes for margins.