¿Cuál es la diferencia entre protégete a tu familia y protégete tu familia ?Puedes dar oraciones como ejemplo.

Both are incorrect, we have three options here.
If you use "protégete" = "protect yourself" that "te" at the end of the verb is the Reflexive pronoun that goes with "tú", for instance: "Protégete porque estás en peligro" = "protect yourself because you are in danger".

Also we can use "protege a tu familia" = "protect your family" we need the preposition "a" because the action applies to someone else, for instance: "Eres el hombre de la casa así que protege a tu familia" = "You are the man of the house so protect your family".

And we can use "protégete de tu familia" = "protect yourself from your family" here the preposition "de" change the idea, for instance "protégete de tu familia, no puedes confiar en ellos" = "protect yourself from your family, you can't trust them"