need help with these 5 translations please!!!! NEED AS SOON AS POSSIBLE!!!!!

Hello, I am writing a children's book for spanish class and I need to know if the following translations are correct (please help!):

A boy that called himself Juan ran...
Un niño quese llamó Juancorrió...

A snowball came out of nowhere and hit him in the head!
¡Un bola de nieve salió de la nada y lo golpeó en la cabeza!

only three snowballs did not hit anyone
sólo tres bolas de nieve no golpeó a nadie

He was getting very cold...
<no translation... could not find one>

They started to throw all of their snowballs at Juan!
¡Ellos epezaron aapuntarle todas sus bolas de nievea Juan!


ANY HELP IS GREATLY APPRECIATED (if you know one of the translations, please say so).
Please help! I can't find how to translate any of this stuff properly and my teacher's a real stickler about grammar... Thank you in advance!

A boy that called himself Juan ran...
Un niño que se llamaba a sí mismo Juan corrió...

A snowball came out of nowhere and hit him in the head!
¡Un bola de nieve salió de la nada y lo golpeó en la cabeza! (very good!)

only three snowballs did not hit anyone
sólo tres de las bolas de nieve no golpearon a nadie (it sounds more natural to me)

He was getting very cold...
(If you mean he was feeling cold as in temperature, it would be: le estaba entrando mucho frío -if it's rather informal- or empezaba a sentir mucho frío)

They started to throw all of their snowballs at Juan!
¡Ellos empezaron a tirar todas las bolas de nieve a Juan!

Hope it helps!


Ro