"We like holiday"
Sikukuu means a specific day, a public holiday or maybe your birthday, an aniversary, etc.
Likizo means a period of time when you don't have to go to work or school. (In American English, this might be "vacation" but I always forget if "vacation" can only be used if you actually go somewhere.)
But yeah ... we have no way of knowing which one is meant in this sentence because it's a completely contextless sentence with bad English as well ... so, either (A) this sentence should have more added to it so we know which kind of holiday is meant, or (B) they should accept both. (A) would of course be better because, with (B), we are not necessarily learning the meanings of the words.