how to stay safe online
1. Immediately close adds that claim you're a winner. Their almost certainly fake.
2. Don't give away your personal information to unknown contacts. Nobody knows who they are and they could be criminals.
3. Don't use your family name on your account. Goods may get stolen if you do so (like the money in your bank account).
Block the sender, print out the evidence of the message, delete it and report it. If you can't manage to do this, try informing a parent or a teacher about the incident.