Thanks @Katayoon but I'm at stage 2 already.1 - Means your file is in process and sent to one of backlog reduction offices depending on which office had capacity to treat your file.
RPRF - could be that they misplaced your payment proof, or have not looked it at it yet, but you can sort it out later. If they ask for RPRF again at Stage 2 you will send them your payment receipt (hopefully, you still have it) or printout from your credit card statement. I would not worry about it now. That's an easy fix.
They did asked for proof of RPRF which was forwarded to Niagara BRO wiith othe docs since Oct.