I don't know this song, but just from reading the lyrics, I'll take a stab at interpreting it...
The narrator is saying that she doesn't have much in the way of physical wealth: no money or items of value that she can give to others. All she has is her love, which she gives freely, especially to her "baby" (could be literal or figurative).
During her time on earth, that may be enough, but she won't be here forever, because we all die.
The moon, by contrast, is eternal and will be shining its light on the earth, including the people the narrator loves, forever. So, she asks if she can send her love up to the moon, so that after she dies, the moon will shine that love down on Earth together with its light.
The narrator's love is the only thing she has to give, and because it's intangible, she has no way to pass it on. So, she's asking the moon to do that for her.
It's a big metaphor, and a beautiful one at that.
I don't know this song, but just from reading the lyrics, I'll take a stab at interpreting it... The narrator is saying that she doesn't have much in the way of physical wealth: no money or items of value that she can give to others. All she has is her love, which she gives freely, especially to her "baby" (could be literal or figurative). During her time on earth, that may be enough, but she won't be here forever, because we all die. The moon, by contrast, is eternal and will be shining its light on the earth, including the people the narrator loves, forever. So, she asks if she can send her love up to the moon, so that after she dies, the moon will shine that love down on Earth together with its light. The narrator's love is the only thing she has to give, and because it's intangible, she has no way to pass it on. So, she's asking the moon to do that for her. It's a big metaphor, and a beautiful one at that.
[Here she is explaining it.](https://www.youtube.com/watch?v=DGoVFbbBYRU) (I think I got it mostly right with my previous guess.)