Changing my blog locations on my website

Site URL: https://www.augmentum.com.au/articles-list

Hi am trying to change the layout of the blog posts on my website. 

Currently I have all the blogs on one page, with category buttons to take people to different topics. However I have over 30 blogs so they are not all displayed. 

I would like to have a specific article drop down menu on the navigation bar to allow people to click on the topic of interest and then be taken to a page with a summary block displaying all the articles on that topic. 

I already have all of these articles written - is there a way to do this without changing the URLs of the articles and breaking the links? I'm trying to avoid setting up a redirect. 

Thanks for your help!