Why am I getting Yahoo pop-ups on new iMac?

I ran Malwarebytes before posting and it said my computer was clean. The browser I use is Safari. I found

a reference (by googling) to freeware which includes Yahoo in a bundle, but all my apps were downloaded from the Apple App Store. My Mac was purchased new last week from an Apple Store. I just set it up this past Thursday. I'm wondering if the News or Stocks apps are somehow connected with Yahoo. I can't find Yahoo in my apps or in my library.

I did go to Safari Preferences and my chosen search engine is google. When I clicked on "manage websites", google was there but not yahoo. The other sites list were legitimate sites I subscribe to: New York Times, Apple, IMDB. I have not opened any suspicious emails since I set up the computer.

I answered my question, I think. The Stocks app included with OS Catalina is a Yahoo app.

And the Notification preference was turned on, by default, for Stocks. I'm going through all of my default settings now.

Thank you all for your help! I hate default settings in updates!