Almost everyone in the world has a phone and is probably most used for contacting people. There are not a lot of dangers whilst using your phone but here are the couple of dangers.
Bullies use phones as a way to target or upset someone. They do this by sending threatening calls or messages of which could upset you. If you are being bullied, try to stop them from contacting you, tell a parent and stop whoever it is from bullying you.
Be careful of downloading things from the Internet at home or on your phone to your mobile because there could be a virus getting details or money from your phone.