So I want to make a 3d world, and have a few characters be drawn in 3d and a few in 2d (sort of the way the amazing world of gumball is made)
Is it possible?
Of course you can. But if you noticed it in Gumball, the camera is always looking at one angle if the scene includes 2d objects. Unity can interact with 2d and 3d objects at same time, it’s only a matter of ways and practices of doing it.
You can use a canvas or a sprite renderer but you will need a script to adjust its position,rotation based on the camera position/direction.