You definitely have a solid, balanced physique, BUT, you definitely need to add more size all around if you have aspirations of being on a bodybuilding stage. Let me give you some statistics to give a good idea of how you stack up. The best thing I ever did before donning posing briefs was get an idea of heights and 'contest weights' of successful competitors.
You're 5'11, and currently ~183 lbs. You're lean, but not contest lean (which is basically stupidly-lean -lol)
I'm 5'8, and at my last contest weighed in at 178, probably walking onstage at about 180. At my first contest though, I only weighed in at 170 lbs, shredded to shit, but admittedly still needing work.
I've usually competed as a "Middleweight", which ranges from 160 - 176 lbs. Remember though, these weights are after dropping bodyfat levels until they're easily around low-mid single-digit ranges. With your height, I can't imagine you anything less than light-heavyweight (176 - 190) or even heavyweight (190 + lbs). Remember, anyone stepping onstage is most likely usually a good 20, 25, maybe even 30 lbs heavier the rest of the year. As lean as you are in the above photos, you'd have to drop anywhere from 10-15 lbs to really see the details in your legs.
Now, I'm certainly not the be all end all of competitors, but since I can vouch for my own statistics, I hope having these in mind can provide some source of comparison. I think it's safe to say that all first time competitors get a dose of reality when they realize that they're not as big as they though -lol.
Despite all these thoughts, the great news is you're still relatively young, and with only a year of training under your belt, I'm sure you're going to continue to improve no doubt.