Which file to edit and where?

My wordpress blog can be viewed at https://www.uptheshots.co.uk .

I want to edit the theme (Landzilla-From the Swamp) by moving the first topic down a bit and adding 3 or 4 lines of text right at the top.
Here is an image to show what I mean: https://i77.photobucket.com/albums/j80/xxll_martin_llxx/uts-ss.jpg

Where the jagged red lines are thats where I want to place my extra text.

What I need to know:
1) Which file do I have to edit in order to move it down and add some text?
2) Whereabouts in that file do I edit it?

Thanks