According to the Wikipedia description of Feldman's VSS scheme
First, a cyclic group G of prime order p, along with a generator g of G, is chosen publicly as a system parameter. (Typically, one takes a subgroup of (Zq)*, where q is a prime such that p divides q-1.)
Why is it necessary to use a generator g in this process?
What is the procedure to be followed to implement a method which produces this generator for a given prime order group Zp?