how do I protect phone info if someone has put their email and password on my phone and I can't access some things such as downloading apps.
do I need a new sin card. I believe I have this persons password
Just a guess - is this a second hand phone? If so and you have encountered Activation Lock, you will never be able to use the device without the original owner's Apple ID and Password. Perhaps we could give a better answer if you would describe the issue more clearly. If it is Activation Lock, see this link...