Are you putting pressure on yourself to make the "right decision?"
There is no right decision. The only "wrong" decision is no decision. Any choice can be made to work. And since you're new, you are more than allowed, nay, ENCOURAGED to make choices and fuck them up. You're learning, so do things to see where they go!
Do not worry about letting the other player down. Remember, they have just as much an idea of what's going on as you do: none. You can't fuck them up. (Anyone who claims you did fuck them up is a jerk, don't listen to them.) Instead, switch your brain to "being supportive." Anything you do, however small, to support your scene partner is more than welcome.
Also, read: https://www.amazon.com/dp/B00MY67HVI/ref=dp-kindle-redirect?_encoding=UTF8&btkr=1