It's best to walk from the Poly to the TTC and board the Epcot monorail there. If you take the resort monorail at Poly, you have 3 stops before the TTC stop. Then you have to exit down the resort monorail ramp, walk over and walk up the Epcot monorail ramp, to board the Epcot monorail. That's a lot of time and effort. Better to just walk over to the TTC. It's not far.