Cassiopeia

Come in close now, it's time to tell a story Long ago and so many years before we Ever were, ever dreamed we even could be There was her and her very first heartbeat

This was a long time ago?

All alone in the corner of the night sky Spiral bones of a supernova starlight Fell in love with another burning bright she Dreamed of a way to ignite she said,

I feel like the main focus of the story, I'm assuming It's Cassiopeia, feels alone in her world saw someone whom she took an interest in, but she feels that he's such a big deal and he's "burning bright" with a great personality/looks?

Tonight Come on, come on collide Break me to pieces, I I think you're just like heaven why

Cassiopeia wants this persons attention in any way, she doesn't care if they're rude or hurtful. She thinks so highly of them.

Come on, come on collide Let's see what a fire feels like I bet it's just like heaven

Just like heaven Just like heaven

This person is burning bright, so it can be presumed that they're on fire (and the first analogy was to stars, so we can assume that this other character is a burning star) and she wants to get their attention and feel their warmth.