Focus on school

Focus on school
 

"Focus on school"
Is that: Centra en la escuela?

Is that first word in English a noun or a verb?

Its a verb and I am using it as a command, why? Also if I expand the sentence: "Focus on school and read books. This book informs me on many things. You should try it." Would it be this then: "Centra en la escuela y lee libros. Este libro me informa sobre muchas cosas. Tú debes probarlo."

Whether something is a noun or a verb matters very much. I didn't have enough context to know which one it was.

focus = centrarse, concentrarse (infinitives - conjugate for person, number and mood)

Don't overuse subject pronouns. Tú never needs to be used, unless your intention is to be emphatic.

Instead of saying 'you should try it' (how do you try a book?), what else could you suggest about the book or its contents?