I don’t think that there is one best CMS to use for your project. Both Joomla and WordPress are equally good. If you want to build a News Portal then you can choose from a big list of WordPress themes or Joomla templates.
There is one difference between a WP theme and a Joomla template – WP themes are more subject specific and content focused while Joomla templates are more of versatile nature. Maybe on this point, WordPress fares better than Joomla, since a News portal is highly content focused.
If you are already familiar with Joomla, then you can make a better use of it for your project. But, if you want to some insight into WordPress and its working, you can read this blogpost on What is WordPress and How to Create Website Using WordPress? https://blog.znetlive.com/what-is-wordpress-and-how-to-create-website-using-wordpress/