How long it needs from int'l arrival ( included all immigration process) to domestic terminal at PEK

I will be arrive from singapore in T3 at 7.10 AM and try to reach earliest flight to Shanghai. How long it takes to finish all immigration process until I can reach domestic terminal? Is there any flight to Shanghai at T3? Is there any domestic ticket counter in T3? I will put my luggage in left baggage counter. Is there any left baggage counter in domestic terminal? Thank you