This is the exact PowerPoint I use on this first day of school in each of my middle school classes. It is editable, so you can change it and adapt to your specific classes. It includes:
Warm up activity
Rules and consequences
General procedures: class jobs, entering the art room, traffic pattern
A fun art related ice breaker
I included some notes for some of the slides, so you can have an idea of how I run my art room.
Materials Needed: index cards, paper, markers