What do you mean by zero potential?

Hint: Both the charges are of equal magnitude but opposite in sign having zero potential in between them. In this case, the electric field is not zero, and we can say that even if the potential is zero, the electric field does not need to be zero.

Complete answer:
An electric charge is supposed to possess zero potential when it is infinitely far apart from other charges. In such instances, if the charge is shifted towards a positive charge, the potential will rise from zero to a positive quantity; similarly, if it shifted towards a negative charge, the potential would reduce from zero to a negative value.
Potential is related, so it is only the variation in potential (and not the amount itself) that matters – but let us understand that potential is estimated to zero at infinity.
Zero potential signifies that the charges in our arrangement have been cancelled out. For instance, exactly halfway between two identical and oppositely charged point charges, the potential is zero.
If we transfer a particle between any two points of the like potential (zero or not), it does not take any energy. So, if we have a point that possesses zero potential, we can put a new particle there from outside the arrangement (i.e., from infinity) for free.
Potential at any point is always measured concerning another point. There is no such thing as absolute potential. In common, the potential at an infinite range is considered as zero. Potential is a scalar term that indicates that it only possesses magnitude but no direction.

Note: The electric potential is the quantity of work energy required to move a unit of electric charge from a source point to the particular point in an electric field with the almost negligible acceleration of the test charge to withdraw, providing kinetic energy or radiation by the test charge.