Multiple Blogs one site with a purchased theme

I bought this theme: https://themeforest.net/item/chromegt-business-portfolio-wordpress-theme/507264

AS you can see, it has a blog already set up. However, it is limited to one page and asks for all the categories I would like to include in the blog.

Instead, I’d like to have multiple blogs (at least in appearance) while maintaining the blog theme from the ChromeGT theme I purchased.

Ideally, a user will click “Baseball News” in the nav bar and be taken to a blog with nothing but Baseball news. Then the user will click “Football News” in the nav bar and go to a page with nothing but football news.

After reading the past several days, I learned that categories and tags are my friend. I downloaded and installed several different plugins, of which posts by tags was the closest thing to accomplish my goal. However, when I use this plug in and it’s shortcode, the page does not display the posts like the ChromeGT blow page does (with nifty “Read More” Buttons and stuff).

I know very little about code. Where do I go from here?