how can i check to see if someone got into my browser

To add to the chorus of good posting

Set up Face ID on iPhone

If you have setup Facial Identification on an iPhone 14 running iOS 18 ( as per your byline iPhone 14, iOS 18 )

Unless you have giving the passcode to someone or if you have not done so

The Other Person will require having Identical Facial Features as you and then to trick the iPhone into thinking they were you

The chances are slim to non existent

How would someone "get into your browser"? Can you explain? Why do you think someone might have?

This is why we have passcodes (iPhone & iPad) and passwords (Macs) … and screen lockouts.