It is certainly in your best interest to stick with a fairly generic n00b routine for a few months. But yes; given your starting size, and unless you want niche-porn dimensions, you probably don’t wan’t all that much more in length.
After a few months of PE reevaluate based on how your Willie responds. Perhaps you will win your version of the PE lottery and respond easily and quickly with girth. Most don’t, but some do. If the n00b routine gives you mostly length but some girth? Stick with it to the point that you really don’t wan’t any more length as long as it keep delivering girth. Then transition to girth specific workouts.
The newbie routines are easy enough and gentle enough that you can start now. Do that. Then, over the course of a few months of newbie PE, read up on squeezes, clamping, and pumping. Girth specific PE, more than anything else, benefits from your unit being toughened up a bit. So it is all upside for you to do basic PE for a while and hold off on girth only work.