what does ''hola, chula como estas amiga'' mean?
In Mexico "chula" is similar to the PR usage; it would mean "Cutie."
"Chula(o)" alone is cute, but when a grown man is called "Chulo" it is usually a slang expression for "Pimp."
I thought I would note, in Costa Rica, a chulo or chula is a person who takes advantage of (friendship) for personal gain, an opportunist, not really a friend. However from the context of your sentence this definition is not what they meant.