Manifold vacumn ports are places where one or more vacumn lines is attached at a single pipe or junction of multi lines coming directly out of the mainfold. Some lines ar plugged off with a little rubber stopper. You may have to put a "T" in a line inorder not to unplug a necessary module/sensor.
The vacumn resevoir used to be a steel can much like a juice can. Newer version is usually a round black plastic ball, don't rust out, that is mounted either on the firewall or somewhere along the right inner fender under the hood.