You can create a custom post type called blog. This would group all your “blog” posts together. Once you have that done, create a template file called archive-blog.php, this will be the file that you can use to list all your posts under the “blog” custom post type. For a single post view, the template would be single-blog.php.
These files would reside under the parent directory of your theme (or child theme if you’re using a child theme).