how to make sure Safari is my browser

That's 2 different things...

Safari is a Browser, it uses what ever Search Engine you choose,...

Change Search preferences in Safari on Mac

In the Safari app  on your Mac, use Search preferences to change how you search the web and how search results are presented. To change these preferences, choose Safari > Preferences, then click Search.

Change Search preferences in Safari on Mac - Apple Support

Change preferences in Safari on Mac - Apple Support

Rena267 Said:

"I want to make sure Google is not my search engine"

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Verifying the Search Engine:

How to change the Search Engine preference of Safari....

Go Here: Change Search Preferences in Safari on Mac - Apple Support