Is there any way to filter out projects based on category for this page (example: Websites, Emails, Print)?
http://www.pmddesign.com/new-site/portfolio/
You can use Portfolio Shortcode to achieve this as described on the following pages.
There are some differences between two and you have to develop some custom code to display them similarly.
Developing custom code for custom functionality is beyond the scope of support that we provide here.
If you are not a developer then you can consider hiring a developer to develop it for you. You can hire a developer from any freelance site. Colorlib recommends the developer https://www.upwork.com/freelancers/~011652ffec8865c6d5