Does a keurig need to be dipped?
Yes
you mean to drop the WHOLE MACHINE into the pool???
or just the top part, where the pod gets inserted, and maybe where the water goes into the machine?
Entire machine under water and wait a moment until water reaches all areas inside and out. Then let dry for a day or two before plugging into outlet.
Hi please explain the keurig is plastic the metal pin which opens the pod merely serves as a can opener
A “can opener” through which the water flows into the cup. It is not just a can opener.
Is it ok to use a Keurig if I don’t know if it was toiveled? (For example hotels, and others who aren’t aware of this)
Tevilah is only required for items owned by a Jew. A Keurig at a hotel not owned by a Jew doesn’t require tevilah.
If the Keurig is connected to a water source, does it still need tevila?
Still requires tevilah