Canon AE-1 PROGRAM Instructions Manual page 17

Advance the film once. Make
sure the film perforations are
engaged in the teeth of the
film transport sprocket and
the take-up spool.
The film should be taut. If
there is slack. gently turn the
rewind crank in the direction
of the arrow until it stops.
Close the back cover.
17
While loading the film. take care
not to touch the shutter curtain.
the film rails or the pressure
plate (shown in red) ....