Questions about the very basics, please help

Hi there,

I've been trying my best to work through the tutorials, but it's been hard for me to follow.

I'd like to do a very simple task just to make sure I understand the parts correctly.

Let's say I'm a five-year old who knows Docker but not much else. I want to sign into Terra, and run an analysis. The analysis simply accesses a TCGA data set from FireCloud (say any FPKM), multiplies the read_counts by 2, and saves it to my Google bucket.

How do I do this?

Can we start with the first step? How do I make a TCGA FPKM file that is hosted on FireCloud accessible to my method?

Please explain like I'm five. Pictures with code would be greatly appreciated.

Thank you!