How do I fix the double Contacts Info?

[trvcoach]

Bought my Galaxy S9 Plus (T-Mobile).

The store set it up for me, but I've noticed that I have doubled information on most of my contacts. My last phone S7, it was just synced up to my Google contacts.
Are my contacts now on my SIM as well as my Google when the phone was set up for me?
How can I make it to only use my Google contacts?

 

[B. Diddy]

Compare a pair of duplicates, and look to see which account each of them is associated with. If one of them is the "Phone account," then the store setup might have copied your old phone's Google account contacts into the new phone's Phone account. So once the new phone synced with your Google account, it then had those two sets.

As long as you're sure all of your important contacts are in your Google account, try going to Settings>Apps, tap Menu>Show System, then select Contact Storage. Tap Storage, then Clear Cache/Clear Data. Then open Contacts again and give it a few seconds to re-sync. Do you only see the Google contacts now?