newbie

Hi all , I am sure you hate reading that title “newbie” and I am sure a lot will avoid it as I am sure it gets very annoying.
I have a website blog https://www.webentrepreneurs.ie and I have just installed it.
The problem I am having is that I have several pages created but how do I edit the pages by just entering ext etc, as I have a archives page and I want the older posts to go into it after the home page is full, any ideas on this.
I also want to create a newsletter function is there a plugin for this or could someone reccomend one.
Lastly is there a way that I decrease the width on the right hand side of the page and have a bigger area for blog posts, great if anyone could help me out it would be breat , many thanks