I would say подобається (or an appropriate variant of) to say like. I would say люблю to say love. Duolingo accepts, inconsistently, like and love as a translation for люблю. Very confusing! So, can anyone explain? I am sure if your significant other said "I love you" and you replied "I like you" there would be some sparks, and not in a good way. LOL
In Ukrainian there is two common meaning of "люблю":
1) "feel affection" (when you are talking about affection between a man and a woman it is better to use the synonym "кохаю")
Я люблю тебе - "I love you"; Я люблю/кохаю свою дружину - "I love my wife"; Я люблю свою країну - "I love my country"
2) "like/enjoy" (the synonym is "мені подобається")
Я люблю читати/Мені подобається читати - "I like to read"; Я люблю цю книгу/Мені подобається ця книга - "I like this book"
Actually the same thing is in English too: http://www.oxfordlearnersdictionaries.com/definition/english/love_2
In writing the distinction is in question mark only :)
In speaking the distinction is in intonation (The tone of your voice should rise).