У ворот = by the gates

Мура = a typical traditional cat's name (Мурка).
Quite stereotypical, like Fluffy or Mittens.

Не ходи... = don't go there
Муре в рот попадешь = You'll end up in Fluffy's mouth.

Also, "привет форумы" means "Hi boards". Форум is a place/site where we all gather, we are "форумчане"