Is there any extension where you can make promotions for the shop and prices will be updated on catalog and cart too?
Something more advanced than the catalog and cart price rules that are in magento.
I suggest you checking out the Grouped Promotions extension. The plugin is available for Magento 2.0.x, 2.1.x, 2.2.x versions and allows to create fixed promotions and apply different discount rules as well as add and configure promosets on product pages and shopping cart.
Hope it will be of help!
Maybe this module will help you https://amasty.com/special-promotions-pro-for-magento-2.html