Page Template Problem / Content Display

Hi, I’m new to WordPress and have created a site called MyPentagonHell.com using WordPress which has gone very well so far. Although recently I’ve had comments from people viewing the site, that it is hard to follow the story I’m trying to convey.

I decided that I need a page with a chronological list of my posts starting from the beginning. I have created a template with code I found by Google searching which produces a list of all my posts in order. However it is just a blank page with a list ( https://mypentagonhell.com/wp/?page_id=291 )and I would like to retain my header image and general look of the rest of the site for it.

I would be very grateful if anyone could help me achieve this or if anyone has any other suggestions as to how I might display the content to make it easier to follow for new visitors.

Thank you in advance,
David.