"- Як справи? - Добре!"
Translation:- How are you? - I am OK!
No, it is not exactly like in Spanish. We do drop pronouns but only in informal situations, where the language is highly colloquial. There is no strict "rule" for this. It's just stylistically different context.. In this course sentences with omitted pronouns are not accepted.
Translations don't have to be 100% word for word. If I say in Ukrainian "Я добре", there's no verb either, "є" is implicit, but should appear in English.
To give you another example: this course suggests translations such as "Home is where the cat is" for "Дім там, де кіт". Literally, that would have to be "Дім де кіт", or even "Дім є де кіт є" in Ukrainian, or "Home is there, where a/the cat is" in English, none of which is a considered a valid translation.
In English, would you answer just "Well", when asked "How are you?", or would you say "I'm well"?
According to the rules you must write dash (тире –) not hyphen (дефіс -). But if you don't write a book :) no metter what you write. Usually, no one pays attention to it and everyone write hyphen (дефіс -). I even don't know how to type dash (тире –) ;)
If you don't afraid :) read: http://ukrainskamova.at.ua/publ/sintaksis_i_punktuacija/rozdilovi_znaki_pri_prjamij_movi_i_slovakh_avtora/7-1-0-232