Most of central Nabadwip is walkable: the cluster of temples around Poramatala is within a few blocks of the main ghats. Cycle rickshaws are the standard local transport for trips beyond that radius — to the Vidyasagar College area, the Devananda Math, or the train station. Negotiate the fare before getting in; under ₹50 for almost any in-town journey.
To cross to Mayapur, take a nauka (small boat) from the ghat south of Poramatala. The crossing takes about 15 minutes and runs from dawn to dusk. The Gouranga Bridge upstream takes road traffic; auto-rickshaws to ISKCON via the bridge cost ₹150-200 each way.