Attach and retrive multiple pdf files to post or page

You should definitely use Advanced Custom Fields (ACF) plugin. Go for the PRO version, since you might need it’s functionality (it costs less than 20 USD) and will be one of the best WordPress related investments.

You should look at the Repeater field (two of them, one for each section) and put a File field as repeater’s row. They you need to display these fields on the front-end.

The documentation is amazing and easy to understand even for a complete beginner.