Blog Posts Lose Formatting and Links

I am brand new to WP and am having trouble figuring out how to make the blog post excerpts (summaries) show up on the home page with the same links and formatting seen on the actual blog post page.

We’ve chosen Impressio-Lite as our site’s theme. I’ve read different instructions on changing function.php code and having to write code to give it new instructions after removing tags but I’ve never done that before and don’t know how to fix this without having to take a coding class. Step by step instructions would be very much appreciated.