Hand job???

Hello! I'm a fairly inexperienced female. I recently entered a relationship with a more experienced guy. We plan to just start off with a hand job and see where things go from there. We are both teenagers and the rule is that we must leave the door open a crack when we are together. So my questions include: 
1. Do I have to unzip his pants?
2. Is there a good way to keep it hidden in case someone bursts in?
3. Is lubrication necessary? 
And any other tips would be greatly appreciated!!!