If it's a relatively new release, the official website of the production company might give you information on where to watch it. You could also ask in relevant online forums or groups dedicated to movies and animations. People there might be able to point you to the right place, whether it's a new streaming service that has exclusive rights to it or some other less - known source.
Sometimes you can catch it on local TV networks that air movies. Or, try searching on lesser-known streaming services. Just make sure they're legal and reliable.
Well, it might be available on certain cable TV channels that focus on family-friendly movies. You could check channels like Disney Channel or Cartoon Network. Also, some online movie rental services might have it.
The true story of Pinocchio could be found on various online movie rental or purchase services. For instance, iTunes or Google Play Movies. You can also search on specialty streaming services that focus on classic or children's stories.