Translation of certeza

I was tired and still felt a little ill, so that I agreed to meet the other family and they escorted me to the next building. The new family instructed me not to tell anyone where I stayed here.
She found it very unromantic that a man would not declare friendship to a woman. Anyway, after an hour or so they got off at a town called Chetumal which was on the border with Belize, where they lived.
I spoke to my sister's friend and she told me I could stay at her place whenever I wanted. I then played Galaga on one of the computer machines and advanced to a very high level of the game.