@Michael---Ray0 Sounds like the first reservation (was it an inquiry?) has not been confirmed and because of that the second requester was able to make a reservation request because technically neither reservation has been completed. You can reply to the second guest and tell them that a prior inquiry/ request is pending and if it doesn't go through you will accepted his request.
That said, I would accept, all things being equal, the person who is willing to book now as opposed to the one that has to think about it.
The first guest might not even confirm the booking and if you turn away the second you may be left with none!
By the way, there is no "hold" option. Calendar dates are either available or blocked.
