The notion that cutting hair on either the head of face encourages growth is a myth. All that happens is that the cut hair has a sharp edge to it, which feels coarser to the touch, but it idoesn;t encourage or discourage growth.
Some men simply don't producce enough testosterone to produce a full even beard growth. Even if you do, it will take a while to get the growth even. When you shave, it is natural to leave some bristles longer than other, which is not noticeable if you shave regularly, but when the hiar starts to grow, it will grow unevenly, igiving you the half-way 'werewolf' look which can lead you to helping the police with their enquiries (LOL).
Be patient, if your beard grows fairly evenly, wait until there is a resonable amount, and then head to your babrbers for a nice even trim. From there, you can decide on the length of beard you want.