Two blogs on same WP website

We use the posts feature on our website for News. There is a News listing and you click on a headline to go to a specific news item (ie post). Now we want to add a blog and we want to use posts for this as well.

I copied the template for the news page (list page), renamed it Blog and have separated the news posts from the blog posts by use of categories. So far so good. Now I want to change some things on the actual post/blog page (ie. the specific blog page). I guess this is single.php.

My questions:
1. How do I create a copy of the “news post page” for the “blog post page”?
2. How do I select the specific template when I write a blog post?

Thanks!
J