I am unable to do a safety check on my iPhone

I cannot perform a safety check as I get an error. Let me explain I had service with my sons mate and I could not do a safety check as I got this error said an error occurred and I also have problems getting into certain parts if my phone and turning off or on certain things and certain things are locked on my phone. Well I went and got my own service changed my number and my Apple ID and guess what the problem still exist oh I even changed my internet service so really what and wh am I sharing a phone with and who has access to control my phone better than me please explain how this is happening and how they are able to do this without my permission my passwords get changed and this is already to much I did not even put google to use as I noticed another email associated with my emails from google well actually two other emails that I did not put there but all this is still happening please some one EXPLAIN… should I get rid of iPhone cause it is not as safe as it says.

[Re-Titled by Moderator]