Hello, I'm super new to Houdini, liking it so far. I'm trying to set up image planes for a car modeling project, but I can't seem to get it to work. I'm looking to set 4 reference images for front, back, top and side but not using the “D shortcut” method for Viewport background image because I can't seem to move or zoom into the image planes in orthographic views that way. I can't find any good tutorials about this either… If someone would like to help, I'd appreciate it.

Have you tried the ‘Reference Image’ object? You can move it wherever in 3D.