Syncing & updating iPhone

Useful links pertaining to both iTunes replacement starting in macOS 10.15 Catalina and also related to Finder and Syncing iPhone the computer

Use the Finder to sync your iPhone, iPad, or iPod touch with your Mac - Apple Support (CA)

What happened to iTunes? - Apple Support (CA)

Of course you can.

What did you update from? It looks like you used to use iTunes, which was replaced several iterations ago.

The functions that used to be performed by iTunes have been subsumed by the Finder, TV and Podcasts applications.

To sync the iPhone, use the Finder. The iPhone will appear in your sidebar, and when you select it, it should be pretty straightforward from there.