Since you mentioned you are having trouble with jargon I will leave this useful link to you:
Glossary: Learn: Digital Photography Review
I am unsure on what the answers are for the scenarios, I believe the two first are a matter of location, location, location, as for the model, yes you could do with some filter or experiment black and white shooting, that's what overcast days are for, depending on what they need the model to reflect she could either be one with the mood of the day (you know, those gloomy philosophical looking pictures) or contrast with it and look like the image of sheer happiness on gray days by suggesting a colorful outfit!
I hope it kinda gives you an idea, you should kind of experiment yourself though since i could be wrong
I think that glossary will help you get an idea what to talk about, it would also be good for you to read your camera's manual if you haven't done so already, it will help you get familiar with: it try reading what it says and taking a few shots experimenting all stuff it can do; it might help you with knowing what to do in each situation.