You have understood what the camera layer resolution means correctly. What went wrong is likely a very easy mistake to make in v0.6.6 of Pencil2D: you probably have the camera layer zoomed out. When you have the camera layer selected, attempting to move the view or zoom in or out will instead modify the camera position and zoom level. If you do this accidentally, the best way to get it back to a 1:1 ratio is to go to View > Reset while the camera layer is selected.
Since you have already drawn your animatic, these drawings will become much larger than your camera if you reset the view now. While you can resize bitmap images with the select+move tools, there is no way to apply this to all frames. The simplest solution is to export your animatic as a png image sequence with transparency enabled at the current resolution and zoom. Then import those images into a fresh project with the same resolution and no zoom in or out on the camera layer. Then your drawings and any backgrounds you import to that project should both match with your expectations. The drawback of this approach is that it will flatten your current animation into a single layer, and anything outside the camera frame of your first project will be cropped. You can increase the camera resolution of the first project before exporting if there are drawings outside of the camera border that you would like to avoid being cropped.