Furniture:
* Desk
* Chair
* Table
* Whiteboard
* Chalkboard
* Bookcase
* Filing cabinet
* Bulletin board
* Projector
* Screen
Supplies:
* Pencil
* Pen
* Paper
* Book
* Notebook
* Eraser
* Ruler
* Scissors
* Glue
* Markers
* Crayons
* Computer
* Printer
* Laptop
* Smartphone
* Headphones
* Dictionary
* Thesaurus
Other:
* Clock
* Calendar
* Map
* Globe
* Poster
* Plant
* Window
* Door
* Trash can
* Light
* Fan
Specific to certain subjects:
* Microscope
* Telescope
* Beaker
* Test tube
* Bunsen burner
* Scale
* Art supplies (paint, brushes, clay, etc.)
* Musical instruments
* Sports equipment
This is just a starting point, and there are many other objects you might find in a classroom depending on the age of the students, the subject being taught, and the specific school.