To get to Theater Amsterdam take bus 48 from Amsterdam Central Station to the stop: Koivistokade.
The bus stops right next to the parking lot behind Theater Amsterdam. From there it's only a 3-minute walk to Theater Amsterdam.

Parking around the Theater Amsterdam is easy. You can park for free on the streets around the theater (be mindful not to park on private property). Another option is to park for 2 euros per hour at the parking garage with 600 parking spaces (5-minute walk): Parkeergarage Houthavens, Danzigerkade 117, Amsterdam.