좋다 is often used to mean "I like", but because it is an adjective, I think it is best to think of it as "to be good". "Apples are good" = "I like apples". Anyhow, -겠 has a few different usages. But in this case, I believe it is being used to mean "would". So I believe 좋겠어요 is best translated as "It would be good."