[How to show related articles on my website]

Im running a website about health and foods. I would like that at the end of each article, it shows other related articles that I have on my website.

Im relatively new with php and mysql so I figure I have to put every page onto a database table. 

 

I looked already everywhere but all I found is how to do with wordpress. But i'm not using anything like that. 

I made the website myself with css and html and php. 

 

Can somebody help me with a website where they explain how to do?

 

Also I would like that automatically it shows my latest articles in a sidebar. Without anytime adding myself manually.

 

Can anybody help me?