fun camera !
you won't be able to use shutter-on-the-lens if your FP / in camera shutter is wound to anything but " 0 "
the finger button ( front of the case ... chrome &c ) depresses to release the shutter.
don't bother using the slider lever on the side as a shutter trip, you will only have trouble. mine hasn't moved from the "front"
position since around 1988 ... it is kind of silly to think it stops any accidents ...
there doesn't seem to be a way to accidently fire the FP shutter unless you accidently wind put your lens on BULB, stop down,
wind your shutter and then physically depress the chrome finger thing ...
if you can find a copy of lester + morgan ( or lester + lester ) 's book graflex and graphic photography
buy it. the book is THE graflex photography book and will explain everything in great detail. graflex.org
can be very helpful too. lots of people have these cameras and there is a huge knowledge base there, just use the search function ...
have fun !