Hi, I've written 2 comic scripts, and let me tell ya there are many different ways to a comic script. My tip is to separate your script. Envision what you want for each panel then write it out, It's a lot easier this way, trust me. When you have everything laid out in your mind you can just write it out. I would suggest in this way..
Example: Page 1 (4 Panels)
Panel 1 (What's going to be in the first panel)
Wide, exterior view of a mansion in the dark of night.
Caption (What's the 1st panel describing)
A mansion hidden in the darkness, under the faint stars of the night.
Narrator (This is where you put a character name or just a narrator. Then underneath you would put what they say)
"Once every 4 years, the planets a line. They reveal a secret that was believed to be a myth. But actually the myth was all too real."