Nothing undercuts a confident first day like a projector that will not connect or a room you cannot find. Visit your classroom ahead of time if you can, or arrive early enough to test the technology, find the light switches, and see how the seats are arranged. Have your syllabus, your plan for the session, and any handouts ready to go.

Arriving early does double duty. It gives you time to solve problems before students see them, and it lets you greet students as they come in, which warms the room before class even starts. A few minutes of preparation buys you a calm, present start instead of a scramble.