1st Motorized bike build Chain issues please help

[GW's Motorized]

Do you know where he go the wheels from? Also I’m curious if I bought this frame and put my engine on it if the pedals are going to spin around with the sprocket if you get what I’m saying lol. Sorry if it’s a stupid question I’m a beginner

If you get a cnc mount the pedals should be fine. He got the wheels from Bikeberry.com