What do you think of my 1st chapter?

This is good storytelling and a good place to begin. Your writing is strong. There are some mistakes that you will catch when you edit. There is some confusion early about who Derek is watching at first. I think it's just a rough transition from one room to the next but you can look at your fourth paragraph and fix it. Watch your commas, you're sticking them in some places where they're not needed and you're using some attributions that you should cut. An example would be here: ""Director?" Derek asked, not budging an inch from his position." which could be: ""Director?" Derek didn't budge." And another is" ""Was that really necessary sir?" Derek asked, his face an expressionless mask." This would read better as: ""Was that really necessary, sir?" Derek's face was an expressionless mask." These are small technical things that you can learn, you have the storytelling and that's the hard part. Keep up the good work.