There is no minimum grip for any of the lifts. For the bench press you can't be any wider than having one finger on the ring (pointer finger). Some feds allow a thumbless grip on the bench, some don't, not sure about the APF. For deads and squats your grip can be as wide as you want, although most feds say the hands must be on the bar and can't be out on the weights (as some might do with squats). For the O rings you should clarify if the person is talking the rings in the normal part of the bar that you hold when you lift, which should be 81 cm apart, or the sleeves of the bar where the weights go. You usually can not grip the sleeve in a meet.
If you compete in gear you can wear knee wraps, bench shirts, and squat suits, nobody currently allows elbow wraps. Nobody allows barefooted lifting to my knowledge.
Good luck with it and hope you enjoy the meet. Open light and go from there,