Inform your parents if anyone bullies or threatens you. Timely action is necessary.
Online friends or chat buddies might not be disclosing their true identities. Select an appropriate chat nickname. Others will only see your nickname when you send them a message; it should reflect that you deserve to be respected.
It is best not to meet chat friends face to face but if you really want to, tell your parents, take an older friend with you and always meet in a public place. Be wary of marriage proposals or invitation to meet alone.
Keep in mind the time you are sending a text; late night and early morning messaging might inconvenience another.
Send and forward messages that bring you respect, people assess your mindset by the messages you send.
Remember that these devices are made to ease your life, not bring added pressure. Use them discretely.
Treat people with the respect, as you would expect for yourself.