"de tu niñez" means "from your childhood"
De tu means: of your in English.
nombre de tu estado= name of your state
a inventor
Translation: Use "tu" when you speak to me, not "Ud.". (Literally: Speak to me of "tu" not of "Ud.".)
Tu es de Paris means you are from Paris.
"Tu eres de Venezuela" means You are from Venezuela
De quelle nationalité es-tu? = What nationality are you?
I have of you.
I think you mean: "De moi si tu m'aime". In English: It's from me if you love me.
tu es l'amour de ma vie - you are the love of my life
Your brother's mother is your (mother, presumably)
"Combien de frères as-tu?" means "How many brothers do you have?" in English.