How do u know when someone has a tracker on your phoneor has access to you phone with you knowing

Also, check your device list to see if there is a device signed in that you don't recognize. You can remove the device using the steps in the article below. As a precaution, change your password.

Apple ID device list -Check to see where you‘re signed in.   * 

 Apple ID Password Change.   -  

ASC YouTube for How to reset your Apple ID password

 What to do after you change your Apple ID or password - Apple Support  -   I suggest doing this before you change your Apple ID or password.

iPhones are very difficult to hack. Unless you have jailbroken your phone, or someone had physical acces to your unlocked phone for a prolonged period of time, you're fine